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.

The effect of isotretinoin treatment on plasma homocysteine levels in acne vulgaris.

Isotretinoin has revolutionized the treatment of acne by improving the cosmetic outcome and decreasing the psychological damage. However, use of isotretinoin is associated with significant side-effects such as mucocutaneous involvement, dyslipidaemia and liver dysfunction, as indicated by increases in liver enzymes. The responsible enzyme for homocysteine metabolism, cystathionine-beta-synthase, might also be affected by isotretinoin-induced liver dysfunction, which leads to hyperhomocysteinaemia, an independent risk factor for thrombovascular diseases. The aim of this study was to evaluate homocysteine levels and the responsible vitamins for its metabolism in patients with moderate to severe acne vulgaris on isotretinoin treatment, before and after treatment. We found increased level of homocysteine in patients after 2 months of taking isotretinoin. Our findings suggest that isotretinoin may increase the risk of cardiovascular disorders by causing hyperhomocysteinaemia.

Androgenic alopecia and insulin resistance: are they really related?

BACKGROUND: Androgenic alopecia is known to be androgen-dependent. Insulin is found in hair follicles and may play a role in the regulation of androgen metabolism and the hair-growth cycle. OBJECTIVES: To compare the insulin resistance between people with androgenic alopecia and a control group. METHODS: A case-control study was conducted with 97 cases in the patient and 87 in the control group. Serum fasting insulin level, fasting blood glucose, serum total cholesterol, triglyceride and high-density lipoprotein (HDL) were all measured in both groups. RESULTS: There was no difference in serum fasting insulin level, fasting blood glucose, serum total cholesterol, triglyceride, HDL and insulin resistance between the two groups (P > 0.05). CONCLUSION: Despite previous reports suggesting a link, our study found no significant relationship between insulin resistance and androgenic alopecia. Further studies are warranted.