Acne Vulgaris
Definition and Pathogenesis
Acne vulgaris is a chronic disorder affecting the pilosebaceous units (hair follicles and sebaceous glands) of the face, chest, and back. Four things must be present for inflammatory acne to develop: androgen-stimulated sebum production; Propionibacterium acnes, an anaerobic diphtheroid of the normal follicular flora that proliferates in response to increased sebum; altered keratinization and desquamation of the cells lining the follicles; and a host inflammatory response.
Sebum production tends to be greater in people with acne than in those without acne. It is stimulated by androgens, primarily testosterone in males and testosterone and dehydroepiandrosterone in females. Sebum provides a favorable environment for proliferation of the P. acnes, which in turn metabolizes sebum, yielding glycerol and free fatty acids. These free fatty acids are believed to promote keratinization andimpaired desquamation of the follicular epithelium, leading to plugging, seen clinically as closed and open comedones (i.e., white- and blackheads, respectively). P. acnes also causes inflammation directly, triggering the release of proteolytic enzymes, hyaluronidase, and neutrophil chemotactic factors, resulting in erythematous papules and pustules. If enough follicular damage occurs, the contents of the follicle spills into the dermis, causing an intense host response, seen as an acne cyst (pseudocyst).
The age old question about dietary factors in the pathogenesis of acne has recently re-surfaced. Although physicians have tried to dispel the “myth” that chocolate, greasy foods, and soda do not cause acne, a study seems to suggest that there may be something to these beliefs that diet may affect acne (1). A group of investigators have proposed that diets rich in refined sugars may be linked to acne. They have examined two non-Westernized people groups, the Kitavan Islanders of Papua New Guinea (n = 1,200, with 300 between the ages of 15 and 25 years) and the Achè hunter-gatherers of Paraguay (n = 115, with 15 between the ages of 15 and 25 years), and found these two groups have no acne. These groups consume diets of all and mostly unrefined foods, respectively, in obvious contrast to the Western diet. These investigators claim that acne is “a disease of Western civilization” modulated by a Westernized diet. Mechanisms proposed for the association relate to dietary-induced increases in insulin causing an increase in insulinlike growth factor-1 (IGF-1), a decrease in IGF-binding protein-3 (IGFBP-3), and an increase in androgens with resultant keratinocyte proliferation, causing plugging of the follicles, as well as enhanced sebum production. Finally, these researchers have proposed a low-glycemic load diet, providing a list of unrefined foods with corresponding glycemic load, as a possible therapeutic modality for acne. Even if they are correct about this association, dietary modification in the second decade or even later in life may not have the same impact on acne as institution at birth or before adrenarchy; however, no one can argue with the other benefits to be reaped from unrefined foods.
Epidemiology
With an estimated 45 million people affected, acne is the most common skin disease in the United States. Acne not only affects over 85% of adolescents and young adults (age 15 to 24 years) but often persists, develops for the first time, or recurs in the third, fourth, and fifth decades (2, 3, 4). A community-based study from the United Kingdom found that among 749 adults, the overall prevalence of clinical acne was 12% in women and 3% in men (5). Physiologic or minimal acne prevalence was 54% in women and 40% in men. Acne may contribute greatly to psychosocial problems such as depression, anxiety, self-imposed isolation,
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and a negative body image. Successful acne treatment usually corrects or significantly improves these problems.
Clinical Presentation
The earliest changes in acne may be seen in the prepubescent years with the appearance of closed and open comedones i.e., white- and blackheads, respectively. As the disease progresses, erythematous, follicular papules, pustules, and cysts may develop on the face and upper trunk. Patients may be asymptomatic or complain of itching and soreness; they often find it impossible to resist physically manipulating, that is, squeezing the lesions.
Evaluation
Before one can determine the course of treatment for a patient, both the clinical severity of the disease and the impact of the disease on the patient must be appreciated. In some, acne may be extremely distressful, and unless asked, most remain silent on the issue.
A tragic suicide in a teen taking the acne medication isotretinoin (Accutane) raised concern about a possible association of isotretinoin depression and suicide risk. Although two large population-based cohort studies (in the United Kingdom and Canada) have not found any association between isotretinoin therapy and increased risk for suicide, depression, or other psychiatric disorders, the issue is still under study. Regardless, the clinician should be vigilant to recognize depression among patients with acne. Recognizing and addressing the potential psychological impact that acne has in patients may be the most important part of acne therapy (6,7). Indeed, addressing this while treating the severe acne with isotretinoin may reduce pretreatment depressive symptoms (8).
When patients present with acne, one should ask about past and present use of over-the-counter and prescription topical and systemic therapies. Poorly tolerated and ineffective medications should not be prescribed a second time. All over-the-counter (OTC) and prescription medications should be reviewed. Drugs that may cause or aggravate acne include hormonal contraceptives that have progestins with greater androgenic effects (e.g., levonorgestrel as in Norplant); corticosteroids; lithium; iodides; phenytoin; anabolic steroids; and high dosages of vitamins B2 (riboflavin), B6 (pyridoxine), and B12 (cyanocobal-amin) (9).
Examination of the face, chest, back, and upper arms is done to determine the type of acne (e.g., comedonal, inflammatory, papular–pustular, or cystic/nodulocystic) and whether scarring has occurred (e.g., ice pick to soft undulations creating shadows). Although most patients with acne have normal androgen levels, females should be assessed for evidence of androgen excess with review of the menstrual and reproductive histories, evaluation of the scalp for possible androgenic alopecia, and examination of the face, presternal chest, upper abdomen, upper back, and trunk for evidence of hirsutism. Abnormal findings warrant evaluation beginning with serum testosterone and dehydroepiandrosterone sulfate (10). Chapter 101 provides a discussion of abnormalities in this hormonal axis.
Before proceeding with an individualized treatment plan, patients should be asked how acne affects their lives: whether there are any activities or interactions they avoid because of their acne; whether they worry, become anxious, distressed, or depressed about their acne; and whether there are other problems related to their acne. Additional screening for depression should be performed as indicated. Obviously, an individual whose self-image has been negatively affected by acne should be given more aggressive therapy than a teen who is unfazed by acne.
Therapy
Successful acne therapy (with the exception of isotretinoin therapy) is expected to control, not cure, acne (Table 115.1). Flexibilty is extremely important, remembering that the patient is the best judge of frequency of topical dosing; a little irritation is to be expected while excessive irritation is uncomfortable, unattractive, and quite frustrating for patients. A given treatment should be used for at least 6 to 8 weeks before assessing its effectiveness. Ultimately, if improvement is suboptimal or the acne is causing scarring, referral to a dermatologist is appropriate.
Although dermatologists, generalists, pediatricians, and gynecologists have been treating acne with success for many years, a review by investigators from the Agency for Health Care Research and Quality, under its Evidence-based Practice Program has concluded that, “There is no basis from controlled trials to judge the efficacy of any treatment in relation to the sequence of therapy. There is still much work to be done to define the best approach to management of acne in an individual patient based upon his or her specific characteristics”(1). This is a good reminder that treatment must be individualized and the best chance for success occurs when the patient and physician are working together.
Comedonal Acne
Comedonal (white- and blackhead) acne responds nicely to comedolytic agents. These agents essentially “unplug” comedones by promoting normal desquamation of the follicular epithelium. Available products include over-the-counter salicylic acid (Neutrogena Clear Pore gel, Clean and Clear Continuous Control Acne Wash, Neutrogena Acne Wash, and Neutrogena Skin Clearing Oil Free Foundation or Pressed Powder for females) and prescription topical synthetic vitamin A derivatives (retinoids), such
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as tretinoin (Retin A and Avita), adapalene (Differin), or tazarotene (Tazorac). Although all these agents work through a similar mechanism, they vary in their therapeutic effects and irritancy effects. A mild agent is tretinoin cream 0.025% and a very strong agent is tazarotene gel 0.1%.
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TABLE 115.1 Acne Therapy |
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When prescribing topical retinoids, patients should be instructed in the following fashion: carefully read and follow the medication instructions included with the product; expect mild irritation; and titrate to tolerance, that is, if daily application is excessively irritating, reduce the frequency of application to two, three, or four times per week, as tolerated. Patients need to know that dosing frequency is best left up to them and that it may vary over time (e.g., twice weekly application in the dry, cold winter months versus daily application in the hot, humid summer months). Because all retinoids are teratogenic, topical retinoids should not be used in persons presently pregnant or considering conception. Specifically, tazarotene is included with Pregnancy Category X medications and thus proper testing to exclude pregnancy when starting therapy and adequate birth control measures to prevent pregnancy must be used in conjunction with therapy. The remaining topical retinoids are Pregnancy Category C medications. Caution is also recommended regarding use in lactating women. The clinician not familiar with these agents should read the manufacturers’ summaries before prescribing topical synthetic vitamin A derivatives.
Inflammatory Acne
Mild inflammatory acne consisting of comedones and erythematous papules with or without pustules (usually up to 15 papules) may be treated with a combination of a comedolytic agent (see above) and a topical antibacterial directed at P. acnes. Appropriate antibacterial agents for
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this condition are topical benzoyl peroxide (uniquely free of problems with the development of bacterial resistance), sulfacetamide/sulfur, and clindamycin preparations. Benzoyl peroxide is a primary irritant, so low concentrations are best (2.5% to 5%) in all patients, except those with exceptionally excessive sebum, in whom a more concentrated gel (8% to 10%) is helpful because of its drying effect. Benzoyl peroxide as a leave-on gel or wash-off cleanser is available over-the-counter (e.g., Oxy Sensitive Skin Treatment 2.5% gel or Oxy 10 Acne Treatment 10% gel; Oxy Clean Moisturizing Face Wash or Medicated Cleansing Bar) and by prescription (e.g., Brevoxyl 4% or 8% Gel, Cleansing Lotion or Creamy Wash, Benzac AC 2.5%, 5%, or 10% Gel). Daily or less frequent use as tolerated is recommended, to be adjusted by the patient. If intolerance or allergy occurs with benzoyl peroxide use, topical sodium sulfacetamide and/or sulfur cream or lotion (e.g., Acnomel cream [OTC] or Klaron lotion) or clindamycin 1% (e.g., Cleocin T Pledgets, Cleocin T Gel) may be substituted. Benzoyl peroxide and tretinoin should not be applied simultaneously because of resultant oxidation of the latter; therefore, one is used in the morning and the other at night. Topical antibiotics and tretinoin may be applied together. The patient may use medicated (as mentioned under comedonal acne) or nonmedicated makeup, as long as it is oil free.
For females interested in possible hormonal therapy, an oral contraceptive pill (OCP) may be offered if not otherwise contraindicated. In teenagers younger than 18, this discussion must always include a parent or guardian. Because of the moral issues that arise for some families regarding an OCP, a physician should never be insistent on this therapy. The effects of estrogen-containing OCPs, which are believed to lead to improvement in acne are reduced ovarian androgen production and enhanced sex hormone-binding globulin (SHBG) synthesis, leading to decreased free testosterone. Although Ortho-Tri-Cyclen (35 µg ethinyl estradiol and 0.180-, 0.215-, 0.250-mg norgestimate) has the U.S. Food and Drug Administration (FDA)-approved indication for acne therapy, Yasmin (30 µg ethinyl estradiol and 3 mg drospirenone) may be more effective because of its unique progestin component which is an analog of spironalactone and, like spironalactone, acts to block androgen receptors. A randomized, double-blind, multicenter trial of women with mild to moderate acne vulgaris given Yasmin (n = 568) or Ortho Tri-Cyclen (n = 586) for six cycles found Yasmin to be modestly superior in effecting total lesion count reduction and in the resultant investigator's and subject's assessment of the therapeutic effect (p ≤ 0.02) (11). Generally, OCPs containing norgestrel and levonorgestrel (e.g., Lo/Ovral, Triphasil) are probably best avoided, as other progestins are available with lesser androgenic effects. Finally, low-dose estrogen OCPs (20 µg ethinyl estradiol) would not be expected to be as beneficial as those containing 30 µg because of lesser effects on SHBG synthesis and thus free testosterone levels.
Although a recent study has suggested that oral antibiotics alone (oxytetracycline 1 g/day or minocycline 100 mg per day) are no more effective for “mild to moderate inflammatory acne” than topical benzoyl peroxide alone (12), dermatologists generally use oral antibiotics in combination with topical agents (especially important is topical benzoyl peroxide to prevent the development of resistant P. acnes) in patients who do not respond to topical benzoyl peroxide and tretinoin. Generally, if inflammatory acne does not improve after 6 to 8 weeks of topical therapy or if a patient initially presents with moderate or severe inflammatory acne or inflammatory acne of any severity that is negatively affecting self-esteem, treatment traditionally includes an oral antibiotic, such as tetracycline 500 mg two times a day (if nausea develops, a reduced dose of 250 mg two times a day may be tried), doxycycline 100 mg two times per day (patients must be cautioned about associated photosensitivity), or minocycline 100 mg once to twice daily. Especially with extremely determined and/or compliant acne patients, it should be made clear that if the medication is making them feel nauseated (due to tetracycline most often), “not so good,” depressed (due to minocycline most often), or causing headache (due to minocycline most often) or severe headache (as in pseudotumor cerebri, which requires immediate attention, and is possible with any of the tetracyclines), the antibiotic should be stopped and another substituted. Also, cautioning the patient about these potential side effects, including depression, may open yet another door for her or him reveal depressive symptoms, if present. Oral antibiotics are always used in combination with topicals, in anticipation of tapering or discontinuing oral therapy after several weeks or months while continuing topicals alone (Table 115.1). Patients should be told that antibiotics only suppress and do not cure acne. Therefore, as long as a patient is still in his or her “acne years” (the duration of which is always difficult to predict), ongoing treatment is necessary. Patients on long-term oral or topical antibiotic therapy should be watched for the development of P. acnes antibiotic resistance, characterized by worsening or flaring of previously well-controlled acne (13).
Other possible causes of sudden worsening or lack of improvement with oral antibiotic therapy include secondary folliculitis because of resistant Staphylococcus aureus, gram-negative bacteria, and yeast (pityrosporum). An additional possible exacerbating factor to consider in females includes androgen excess; despite initial evaluation for this, clearly a patient could develop an excess or manifestations thereof at some point after initially seeking treatment; thus, repeated clinical and laboratory evaluation should be considered. Yet another cause for worsening or nonresponsive acne in male and female teens and adults is anabolic steroids use; change in body physique,
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androgenic alopecia (male and female patterned hair loss), and striae in both genders, gynecomastia in males, and reduction in breast size, change in vocal tone, and hirsutism in females may also be present.
Cystic Acne
Cystic acne, characterized by deep-seated, inflammatory, nodular cysts, should always be treated aggressively to prevent permanent scarring. If patients do not respond to oral antibiotics in combination with topical agents in 6 to 8 weeks, referral to a dermatologist should be made. Although the dermatologist may prescribe an alternative nonretinoid therapy, it is likely that the systemic retinoid isotretinoin (13-cis-retinoic acid, Accutane) will be needed. Isotretinoin is “curative” in approximately 70% of patients, although the basis for this is unknown. The greatest concern with isotretinoin is its teratogenic potential. It may produce fetal anomalies involving the central nervous system, heart, bones, and thymus in 30% to 40% of exposed fetuses. All women of child-bearing age must be counseled on the use of two concurrent forms of contraception (see Chapter 100). In the very unlikely event that pregnancy develops, an abortion is usually recommended. It is wise to establish whether a patient is morally against abortion before beginning therapy. If this is the case, to guarantee the risk of pregnancy is zero, this individual should remain abstinent from sexual intercourse for the 20- to 28-week period of treatment, as well as for 1 month before and after treatment, or forego isotretinoin therapy. The maker of isotretinoin (Roche Dermatologics) has developed a patient instruction/consent form packet that is critical for both the clinician and the patient to review carefully.
Some side effects with isotretinoin therapy are essentially inescapable. These include dry skin, lips, nose, and eyes. Mild elevations of triglyceride, cholesterol, and liver enzymes are seen in approximately 25% of patients. Infrequent or unusual side effects include hair loss, musculoskeletal aches, S. aureus folliculitis and ocular keratitis, reduced night vision, marked elevation of triglyceride with the potential for an associated acute pancreatitis, marked elevation of cholesterol and liver enzymes, leukopenia, and pseudotumor cerebri.
Some patients developing triglyceride elevations may have an inherited familial lipid disorder (14) and a useful patient summary regarding this unusual side effect of isotretinoin therapy is available (15).
Rosacea (Acne Rosacea)
Acne rosacea, usually referred to as “rosacea,” is a chronic inflammatory disorder favoring the central portion of the face. It occurs most commonly in fair-skinned whites with blue eyes. Affected patients usually develop initial signs of the disease in their twenties or thirties with central facial erythema, exaggerated flushing, telangiectasias, and intermittent erythematous follicular papules and pustules and edema. Rarely, patients may develop associated rhinophyma; this bulbous nose enlargement is seen more often in men than in women and is caused by hyperplasia of the sebaceous glands. Rosacea does not cause comedones and therefore can be differentiated from acne vulgaris. However, occasionally patients have both rosacea and acne.
Rosacea may also involve the eyes, causing a mild inflammation of the lid margins manifest by mild erythema and causing the sensation of dry or scratchy eyes. Other slightly or somewhat less common changes include conjunctivitis, blepharitis, episcleritis, and recurrent chalazion and hordeolum (see Chapter 109). Less than 5% of patients with rosacea develop a painful and vision-threatening condition of the cornea, rosacea keratitis.
Although the cause of rosacea remains unknown, the condition is characteristically so well controlled with antibiotics that lack of a clinical response should raise a question about the diagnosis. Mild disease is generally treated with topical therapy alone. However, for patients with ocular symptoms, a moderate number of papules, or with burning and stinging, systemic treatment is preferred: tetracycline 500 mg, doxycycline (photosensitizing) 100 mg, or minocycline 100 mg, once to twice daily. If a good response is seen, the dose may be reduced at 1 and 2 months and then the drug discontinued at 3 months, switching over to topical therapy alone. If a flare occurs, the oral antibiotic may be restarted and tapered again. Although some patients can discontinue therapy after several months, most flare without some therapy. For long-term treatment, topical therapies are generally preferred and include metronidazole gel, lotion, or cream (MetroGel, -Lotion, -Cream, or Noritate Cream), sodium sulfacetamide and or sulfur products (e.g., Rosac cream, Klaron lotion, and Acnomel cream [OTC]), and azelaic acid (Finacea gel) applied to the affected central face once to twice daily after washing.
Hidradenitis Suppurativa
Hidradenitis suppurativa is characterized by inflammation and occlusion of follicles in areas where apocrine glands are found. Onset is usually in the late teens or early adult years, and disease may persist for decades. Sites where apocrine glands are normally present, or, where ectopic apocrine glands are sporadically present, are affected. These sites include the axillae, perineum, inguinal folds, pubic region, and often the umbilicus, breasts, postauricular area, scalp, and back. Affected areas are studded with large comedones, inflammatory papules, pustules,
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and cysts. Sinus tracts form when cysts rupture and may drain serum, blood, or purulent material. Patients may also have cystic facial acne and scarring scalp folliculitis.
Complications of and associations with hidradenitis suppurativa may include secondary amyloidosis, anemia of chronic disease, sacroiliitis, and depression. Finally, patients are at risk for episodes of acute bacterial cellulitis and, after many years, squamous cell carcinoma (SCC) in this chronically inflamed tissue.
The differential diagnosis of hidradenitis suppurativa includes recurrent bacterial folliculitis and furunculosis (see Chapter 32), scrofuloderma (Mycobacterium tuberculosis infection with an ulcerated draining lymph node), granuloma inguinale (Calymmatobacterium granulomatis, a sexually transmitted disease (STD) characterized by genital and inguinal sinuses and hypertrophic scars), lymphogranuloma venereum (see Chapter 37), Crohn disease (see Chapter 45), and a pilonidal cyst. The diagnosis of hidradenitis suppurativa is made by recognizing comedones, which are not present in these other disorders. Skin biopsies for histopathology and tissue cultures may be required to exclude other diagnoses.
The pathogenesis of this disorder is not well understood. It is debated whether infection in these patients is a primary or secondary event. Treatment consists of short courses of antibiotics for acute secondary infection. Specific antibiotic therapy should be based on the results of culture taken from draining lesions. Chronic ongoing therapy may include oral tetracyclines (e.g., doxycycline 100 mg twice daily), chosen for their anti-inflammatory and antibacterial effects, and topical benzoyl peroxide to reduce the risk of bacterial resistance, in a regimen similar to that used in acne (see Inflammatory Acne). Adjunctive oral contraceptive therapy may be beneficial in some women. Surgical therapy ranging from tract marsupialization to deep wide excision should be considered for patients with severe disease. Although investigational, there have been several case reports and one case series reporting improvement in patients treated with infliximab (alone or in combination with other therapies) (16); controlled trials are clearly needed to determine whether this is an acceptable therapeutic option for this debilitating and very difficult to treat chronic condition.
Miliaria
Miliaria is a disorder of sweat retention caused by occlusion of the ducts of the eccrine glands. Unlike the sebaceous and apocrine glands, which secrete through the hair follicles to the skin surface, eccrine glands are separate from hair follicles. They are directly connected to the surface of the skin through eccrine ducts. Although it is not a follicular disorder, as are acne and folliculitis, it may mimic these disorders. Miliaria occurs most often in active people who are perspiring heavily and who are wearing occlusive clothing or are confined to bed for extended periods.
The eruption almost always occurs on the trunk. When the sweat duct is occluded very superficially, asymptomatic, noninflammatory, 1- to 2-mm vesicles that easily rupture are seen in the upper central chest or back (miliaria crystallina), creating a distinctive appearance. When the duct is occluded deeper in the skin, pruritic, nonfollicular, erythematous papules occur over the chest and back (miliaria rubra). Lesions may be few to many in number.
The differential diagnosis of miliaria rubra includes infectious and noninfectious folliculitis. These forms of folliculitis are distinguished by their involvement of hair follicles as opposed to the eccrine ducts.
The treatment of miliaria includes providing a cool environment, removing occlusive clothing, and modifying positioning in bedridden persons. Cool baths and topical antipruritic lotions containing menthol or phenol (e.g., Sarna lotion) may reduce pruritus when present. Drying lotions (e.g., Zeasorb AF lotion/powder) may also be helpful.
Noninfectious Alopecia: Nonscarring and Scarring
When assessing the chief complaint of hair loss, it is helpful to understand normal hair physiology. Every individual hair may be classified based on whether it is growing, transitional, or resting. These phases are anagen (lasting 2 to 6 years), catagen (lasting 2 to 3 weeks), andtelogen (lasting 2 to 3 months), respectively (17). Scalp hair loss in excess of normal shedding or alopecia involving the scalp may benonscarring or scarring; fortunately, nonscarring alopecia is far more common.
Nonscarring Alopecia
Nonscarring alopecia is so designated because the affected hair follicles are not permanently lost or damaged. Clinically, noninflammatory and nonscarring alopecia (hair loss without visible changes of erythema, scale, scarring) is characteristic of male and female pattern hair loss (androgenetic alopecia), alopecia areata (histologically inflammatory), telogen effluvium, anagen effluvium, and various systemic causes of diffuse hair thinning, including thyroid disease, systemic lupus erythematosus, and drug-induced hair loss.
Androgenetic alopecia is common in both men and women. Typically, men experience a frontal and vertex type of thinning, variably followed by confluence over the entire crown (top of the head); in contrast, women experience mild to moderate thinning over the entire crown with notable sparing of the frontal hair margin. In both genders, the onset of androgenetic alopecia may be as early as the late teens. Rarely, women show a male pattern of
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hair loss. In all women with hair loss, regardless of the pattern, one should look for signs of virilization (e.g., facial, upper chest, upper back, and upper abdomen hair growth; clitoral hypertrophy; deepening voice; and muscular body habitus). Appropriate evaluation should be performed to exclude hyperandrogenemia caused by adrenal hyperplasia, polycystic ovary disease, insulin resistance (18) that is often accompanied by acanthosis nigricans, a velvety hyperpigmentation around the base of the neck and axillae, and various adrenal and ovarian tumors (see Chapter 101). Additionally, women who are taking testosterone (e.g., Estratest), progestational drugs with greater androgen effects (e.g., levonorgestrol), or over-the-counter dehydroepiandrosterone should be told that these agents aggravate androgenetic alopecia and are best stopped.
Treatment options in patients who desire more hair include oral finasteride (Propecia, 1-mg tablets) for men and topical minoxidil, hair transplants, and various hair prostheses, varying from woven-in individual hairs to full-scalp wigs, for both women and men. Each of these treatments has its disadvantages. OTC topical minoxidil 2% solution (Rogaine) produces significant hair growth in only approximately 20% of patients; however, a greater percentage of patients have a reduction in further hair loss. Rogaine Extra Strength for Men (minoxidil 5% solution) is also available over-the-counter and is said to grow 45% more hair than the 2% Rogaine. Oral finasteride or topical minoxidil therapy must be ongoing to maintain hair growth, at a cost of $20 to $60 per month. In contrast, hair transplants are permanent. Many patients are very pleased with the results. Hair weaves in which natural or synthetic hair is woven into the patient's own hair must be repeated as the hair grows out. Finally, although some people do well with a wig, they may be uncomfortable, difficult to manage, and costly.
Telogen effluvium is a common disorder in which patients experience shedding of telogen hairs diffusely over the scalp. The percentage of telogen or resting hairs may shift upward to approach 20% (versus normal 10%) of the scalp hair. This amount of hair loss is usually evident only to the patient, who notes excessive hair coming out on shampooing and combing. Telogen effluvium may begin 2 to 3 months after such events as childbirth, general anesthesia, and catabolic states such as high fever for many days, rapid weight loss, and protein malnutrition. This form of alopecia is self-limited; however, several months may elapse before hair loss stops and new anagen hair growth begins. Because (anagen) hair grows approximately 1 cm per month, depending on the individual's chosen hair length, return to the “pretelogen effluvium” appearance may take a year or so. Reassurance of this expected ultimate outcome is extremely important.
Numerous nonchemotherapeutic drugs have been reported to cause hair loss through a variety of mechanisms, primarily affecting telogen hairs (10% to 20% of the scalp hairs), therefore producing a chronic telogen effluvium that is usually appreciable only to the patient. The most common of these drugs are anticoagulants, anticonvulsants, and cholesterol-lowering agents. This hair loss is reversible with discontinuance of the causative medication. If the medication cannot be eliminated, patients should be reassured of the self-limited nature of this side effect.
Anagen effluvium may be caused by chemotherapeutic agents and ionizing irradiation. Patients have shedding of the actively growing hairs in the scalp, which constitute approximately 90% of the total scalp hair. Hairs are shed rapidly over a matter of days, and patients typically have no or only very sparse hairs left on the scalp (the remaining telogen hairs). With the occasional exception of ionizing radiation-induced effluvium, this hair loss is tem-porary.
Alopecia areata is an immunologically mediated form of hair loss that typically presents with one to a few coin-shaped areas of hair loss. Although yet to be determined, it is believed that a certain genetic constitution and triggering factors are necessary for disease expression. Infrequently, patients may have total scalp hair loss (alopecia totalis) or total body hair loss (alopecia universalis). Most patients with just one or two patches of alopecia will have spontaneous hair regrowth within 1 year; however, recurrences in the same or new sites are common. Although most patients with alopecia areata do not have any associated disorders, alopecia areata is associated with an increased lifetime risk of autoimmune conditions, such as thyroid disease, pernicious anemia, and Addison disease. Initial treatment of patients with alopecia areata usually consists of topical corticosteroid solutions (e.g., clobetasol or fluocinonide solution, three to four drops applied to each quarter-sized area, including 0.5 cm of radially encircling normal scalp) or corticosteroid scalp injections. Other treatments (e.g., topical minoxidil, topical irritants, topical sensitizers, photochemotherapy) may be helpful in some patients, but, as with topical and intralesional corticosteroids, well-controlled studies demonstrating efficacy are limited or lacking.
Although still other disorders may cause variable degrees of nonscarring alopecia, the alopecia is merely secon-dary to the primary inflammatory process or because of trauma. Examples of the former include tinea capitis and seborrheic dermatitis and the latter include prolonged pressure-associated ischemia-induced alopecia (e.g., prolonged unrecognized unconscious state, prolonged sur-gery) and trichotillomania (self-inflicted alopecia).
Scarring Alopecia
Scarring alopecia is relatively uncommon. It is characterized by focal scarring with a loss of hair and visible hair follicles. One of the most common forms of scarring alopecia seen occurs primarily in African American women (19).
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After years of chemical permanent solutions and traction, a resultant permanent hair loss favoring the crown and temporal scalp may develop. Similar to our paradigm for the development of nonmelanoma skin cancer with repeated sun exposures beginning in childhood eventuating in skin cancer after the third or fourth decade, the same model may be applied to this externally induced scarring hair loss. As with skin cancer, education to prevent disease must begin in school children.
Causes of scarring alopecia that are independent of external factors are discoid lupus erythematosus, folliculitis decalvans, cicatricial pemphigoid, lichen planopilaris, and pseudopelade (idiopathic scarring alopecia). Scarring alopecia is irreversible in most instances because the scarred follicles are incapable of producing new anagen hairs. Patients suspected of having scarring alopecia should be referred as early as possible to a dermatologist in hopes of preventing further permanent hair loss.
Specific References
For annotated General References and resources related to this chapter, visit http://www.hopkinsbayview.org/PAMreferences.