Subungual hyperkeratosis due to sarcoidosis

A 30-year-old Japanese woman presented to our clinic for evaluation and treatment of subungual hyperkeratotic lesions of the toenails. Five years previously the bilateral parotid glands and hilar lymph nodes became enlarged, and tender subcutaneous nodules developed in the lower extremities. Transbronchial lung biopsies showed epithelioid granulomas and systemic sarcoidosis was diagnosed. A skin biopsy showed nonspecific septal panniculitis, a finding compatible with erythema nodosum. Since then the patient had experienced intermittent episodes of low grade fever, general malaise, dyspnea, diarrhea, and superficial lymphadenopathy, and systemic steroid was administered when the disease was aggravated. The initial erythema nodosum subsided in a couple of months and was replaced by a large number of slightly scaly, erythematous papules and nodules in the lower extremities and in the face. The biopsy specimens of these lesions showed noncaseating epithelioid granulomas in the dermls. These cutaneous lesions waxed and waned along with the systemic symptoms. The patient had never had uveitis or lupus pernio. A few months previously new erythematous papules and nodules had developed in the face and in the lower extremities. Hyperkeratotic verrucous lesions also developed at the hyponychium and beneath the distal portion of the nail plates in all the toenails (Fig. 1a). The proximal and lateral nail folds and the nail plates appeared normal. Repeated potassium hydroxide stain and culture of the subungual hyperkeratotic materials were negative for fungus. Roentgenogram of the toe phalanges was normal. Interestingly, none of the fingernails were affected. A biopsy specimen of the nail bed showed orthokeratotic hyperkeratosis and acanthosis of the epidermis, but no papillomatosis or vacuolated keratinocytes (not shown). There were discrete epithelioid granulomas in the superficial dermis (Fig. 2). Systemic steroid, 30 mg/day, was administered because the patient's lung parenchymal lesions were aggravated. The subungual hyperkeratosis rapidly improved after administrating steroid for 2 weeks (Fig. 1b).