A key to remembering the cause of a mouth pigmentation is found in the mnemonic MINTS.
· M—Malformation would bring to mind familial intestinal polyposis (Peutz–Jegher syndrome) and Fabry disease.
· I—Inflammation would suggest the pigmemtation of the buccal mucosa seen in pulmonary tuberculosis of the adrenal gland leading to Addison disease.
· N—Neoplasm suggests the pigmentation seen in metastatic malignant melanoma and carcinomatosis.
· T—Toxic helps recall the toxic substances that cause mouth pigmentation such as silver, bismuth, contraceptives, tranquilizers, antimalarials, lead, arsenic, and mercury.
· S—Systemic diseases associated with mouth pigmentation include Addison disease, Hemochromatosis, and porphyria.
Approach to the Diagnosis
If lead or arsenic poisoning is suspected, hair analysis may be done. If Addison disease is suspected, serum cortisol or a 24-hour urine 17–hydroxysteroids and 17–ketosteroids should be done. A gastrointestinal (GI) series, small bowel follow-through, and barium enema may be done to rule out Peutz–Jegher syndrome. Urine porphobilinogen and porphyrins will help diagnose porphyria.
Other Useful Tests
1. Rapid adrenocorticotropic hormone (ACTH) tests (Addison disease)
2. Urine melanin (malignant malenoma)