Tongue Discoloration
A 33-year-old woman with celiac disease presented to the dermatology clinic with a 3-week history of painless discoloration of the tongue. She reported that she had not used tobacco or bismuth compounds or consumed colored foods or candies, and she had no amalgam fillings. A progesterone-releasing intrauterine device had been placed in the patient 3 years earlier for contraception, and she had been taking no other medications. She reported mild fatigue but otherwise felt well. Physical examination revealed hyperpigmented reticular patches on the dorsolateral aspects of her tongue, with sparing of the buccal mucosa, palate, gingiva, and other mucosa. Laboratory studies were notable for a normal complete blood count, a normal comprehensive metabolic panel, and normal vitamin B12 and thyrotropin levels. A cosyntropin stimulation test showed an insufficient adrenal response, with a baseline cortisol level of 7.9 μg per deciliter (218 nmol per liter), a 30-minute cortisol level of 9.5 μg per deciliter (262 nmol per liter), and a 60-minute cortisol level of 7.5 μg per deciliter (207 nmol per liter); the corticotropin level, measured in the afternoon, was elevated at 1102 pg per milliliter (243 pmol per liter) (reference value, <20 pg per milliliter [<4 pmol per liter]). A 21-hydroxylase antibody test was positive, a finding consistent with a diagnosis of autoimmune adrenal insufficiency. In primary adrenal insufficiency, skin hyperpigmentation is often generalized and involves sun-exposed areas, the palmar creases, nail beds, and mucous membranes; isolated tongue discoloration is less common. Daily treatment with oral hydrocortisone was initiated, and she was counseled regarding the symptoms of adrenal crisis and the need for lifelong therapy. Within 4 to 8 weeks after the initiation of treatment, the tongue hyperpigmentation had resolved.