Inverse Gottron's papules and mechanic's hands after a tug of war: triggered by friction and pressure?

A 31-year-old female presented with 4-week history of painful rashes on the hands. Six weeks ago, she had been involved in a tug of war, after which she experienced a burning sensation in her palms, followed by papules developing on her hands. On examination, hyperkeratotic, scaling, fissuring lesions (mechanic’s hands) were observed on her fingertips (Fig. 1A and B) and the lateral sides of her fingers (Fig. 1C). On the flexor aspects of the IP joints, tender, hyperkeratotic, dusky red papules were noted, most of which manifested as two separate papules on either side of the joint (Fig. 1D), consistent with inverse Gottron’s papules. Physical examination also showed Gottron’s papules over the elbow (Fig. 1E). She reported shortness of breath for 1 week and denied any muscle weakness.

Fig. 1

Clinical manifestations of the patient

(A–C) Mechanic’s hands. (D) Aligned hyperkeratotic, palmar dusky red papules with a few areas of ulceration, referred to as inverse Gottron’s papules. (E) Erythematosous and fissured papules over the elbow.

Laboratory analysis was notable for positive anti-melanoma differentiation-associated gene 5 (MDA5) antibodies. Serum creatine kinase, malignancy screen and electromyography were normal. Interstitial lung disease was confirmed in high-resolution computed tomography. A diagnosis of anti-MDA5 DM was thus made. She was managed with glucocorticoids and tacrolimus, with which her symptoms improved.

Stretch and movement have been implicated in the pathogenesis of DM [1, 2], but do not receive much attention. In the present case, the strong temporal association and the distribution of papules suggested such movement as a precipitating factor. The minor injuries caused by the friction and pressure might act with, or result in, autoimmunity to promote new-onset DM in genetically susceptible individuals.