Background and aims Rapidly progressive interstitial lung disease is complicated in majority of patients with dermatomyositis who are positive for anti-melanoma differentiation-associated gene 5 antibody (MDA5). Clinically amyopathic dermatomyositis with Heliotrope rash and Gottron’s sign can offer an implication for MDA5-positivity and the critical treatment before uncovering the result of blood testing, since these patients can survive only if they received immediate and intensive therapy.We observed nailfold capillary formation of two acute patients with anti-MDA5 antibody using dermatoscopy in the current study in order to test the capability to predict the MDA5 positivity.

Methods Nailfold of two patients with dermatomyositis were examined using dermatoscopy, (dermlite 3, 3 gen, USA.) MDA5 positivity was confirmed by ELISA.The findings were imaged using I pad mini (apple, USA). The images were compared to the patient with Jo-1, those with TIF1, or centromere.

Results Marked haemorrhages and enlarged capillaries were observed in almost all nailfolds of both hands, while only upto three nailfolds in patients with antibodies against Jo-1, TIF1, or centromere. However, loss of capillaries was not detected under the dermatoscopy at all, while these were detected in capillary scope in the literature in anti-MDA5 antibody positive patients.

Conclusions The results of the current study suggest that nailfold findings using dermatoscopy have a potential to diagnose the patients anti-MDA5 antibodies at their first visit, although there is a limitation in number of patient samples in this study. Likewise, the nailfold findings on dermatoscopy may provide visible information for the pathogensis of interstitial pneumonitis in these patients as well.