Derm Dx: Red lesions on the interphalangeal joints of the hands

This patient presents with Gottron papules, a feature of dermatomyositis. Dermatomyositis is an inflammatory myopathy characterized by skeletal muscle weakness and muscle inflammation. It presents with multiple skin manifestations such as periungual telangiectasias, Gottron papules, poikiloderma, and heliotrope rash.1,2Gottron papules,...

Submit your diagnosis to see full explanation.

This patient presents with Gottron papules, a feature of dermatomyositis. Dermatomyositis is an inflammatory myopathy characterized by skeletal muscle weakness and muscle inflammation. It presents with multiple skin manifestations such as periungual telangiectasias, Gottron papules, poikiloderma, and heliotrope rash.^1,2

Gottron papules, as seen in the image, are erythematous to violaceous scaly plaques located on the joints of the hands and rarely on the elbows and knees. The heliotrope rash is an erythematous to violaceous dermatitis occurring in the malar and periorbital areas of the face. Other skin changes in dermatomyositis include poikiloderma, which is characterized by telangiectasias, atrophy, and dyspigmentation. These skin changes are located characteristically in a photo-distributed area along the neck or on the back, which is known as the “shawl sign.”²

The diagnosis of dermatomyositis is suspected when a patient presents with these cutaneous findings and muscle weakness. Laboratory workup can help confirm or rule out dermatomyositis. Classic laboratory results in dermatomyositis include elevated muscle enzyme levels, including creatinine kinase, lactic dehydrogenase, and aldolase. Further diagnostic testing might include muscle biopsy or electromyography studies.³

Prednisone is considered the mainstay of initial treatment for dermatomyositis.^2,3 This is often combined with an immunosuppressive agent such as methotrexate⁴ or azathioprine.⁵ Refractory dermatomyositis may respond to rituximab.⁶

Megha D. Patel is a student at the Commonwealth Medical College, Scranton, Pennsylvania.

Stephen Schleicher, MD, is an associate professor of medicine at the Commonwealth Medical College and an adjunct assistant professor of dermatology at the University of Pennsylvania Medical College. He practices dermatology in Hazleton, Pennsylvania. 

References

1. Callen JP. Cutaneous manifestations of dermatomyositis and their management. Curr Rheumatol Rep. 2010;12(3):192-197.
2. Callen JP, Wortmann RL. Dermatomyositis. Clin Dermatol. 2006;24(5):363-373.
3. Moghadam-Kia S, Aggarwal R, Oddis CV. Treatment of inflammatory myopathy: emerging therapies and therapeutic targets. Expert Rev Clin Immunol. 2015;11(11):1265-1275.
4. Newman ED, Scott DW. The use of low-dose oral methotrexate in the treatment of polymyositis and dermatomyositis. J Clin Rheumatol. 1995;1(2):99-102.
5. Bunch TW. Prednisone and azathioprine for polymyositis: long-term followup. Arthritis Rheum. 1981;24(1):45-48.
6. Aggarwal R, Bandos A, Reed AM, et al. Predictors of clinical improvement in rituximab-treated refractory adult and juvenile dermatomyositis and adult polymyositis. Arthritis Rheumatol. 2014;66(3):740-749.