A pigmented tongue unmasking Addison´s disease: a rare clinical image

A young female patient presented with complaints of generalized weakness, fatigue, and reduced appetite for several months. On oral examination, diffuse dark brown to black pigmentation was observed over the dorsal surface of the tongue. The pigmentation appeared irregular but asymptomatic and was clearly visible during routine inspection of the oral cavity. Oral mucosal hyperpigmentation is a recognized manifestation of primary adrenal insufficiency and may precede other cutaneous features. Based on the clinical findings and systemic symptoms, further endocrine evaluation was undertaken. Laboratory investigations revealed low morning serum cortisol levels (3.2 μg/dL) with elevated adrenocorticotropic hormone levels (120 pg/mL), supporting the diagnosis of Addison´s disease. Differential diagnoses considered included pigmented fungiform papillae of the tongue, geographic tongue, and drug-induced oral pigmentation. The patient was started on corticosteroid replacement therapy along with supportive management, following which improvement in fatigue and general well-being was observed on follow-up. This case highlights the importance of early recognition of oral manifestations in diagnosing systemic endocrine disorders.