Small-fibre neuropathy in a patient with dermatomyositis and severe scalp pruritus.

Dermatomyositis (DM) is commonly associated with scalp pruritus that can be severe. In addition, significant crawling and burning sensations have been reported in these cases. The aetiology of these scalp sensations in the context of DM is not fully understood. We report a 42-year-old female with treatment-resistant DM and structural changes in scalp epidermal and dermal nerve fibres. The patient presented with characteristic skin manifestations (Gottron's papules and poikiloderma), severely pruritic scalp, intermittent muscle weakness on neurological exam with electrodiagnostically confirmed myositis, and joint pain. Structural changes in scalp epidermal and dermal nerve fibres were discovered in a skin biopsy, suggesting that small-fibre neuropathy associated with scalp pruritus may be a manifestation of the DM syndrome. Further clinical experience combined with selective skin biopsy in patients with DM and symptomatic scalp will help determine the frequency of coexistent small nerve fibre involvement. Based on our limited findings, we suggest that pruritus in DM may be associated with abnormal epidermal and dermal nerve fibre structure.