For Rare Disease Day on February 29, Topical Conversations will be exploring some of the rare diseases seen in dermatology. In this installment, Todd Schlesinger, MD, FAAD, FASMS, gives his perspective on subacute cutaneous lupus erythematosus (SCLE) and dermatomyositis. 

Watch Part 2 to hear Dr Naiem Issa discuss tuberous sclerosis complex and a breakthrough new treatment.

Subacute cutaneous lupus erythematosus 

SCLE is a condition linked to systemic lupus erythematosus in 50% of patients; it may also be associated with Sjögren’s syndrome. SCLE manifests as a small, red, scaly papular eruption in sun-exposed areas, progressing to a psoriasiform or annular lesion. This photosensitive dermatosis is nonscarring and nonatrophic, with lesions healing without scarring but potentially leaving some dyspigmentation. Commonly affected regions include the shoulders, forearms, neck, and upper torso. Around 50% of patients with SCLE patients experience joint involvement, with often symmetrical arthralgias usually affecting small joints like wrists and hands. 

Dr Schlesinger notes that SCLE is a notably challenging condition in dermatology but expresses hope for new treatments in the pipeline, potentially ones that leverage existing medications used for psoriasis and atopic dermatitis. 

Dermatomyositis 

Dermatomyositis is a rare, idiopathic inflammatory disorder primarily affecting the skin and muscles but sometimes also affecting the joints, esophagus, lungs, and heart. It falls within the category of myositis, a rare group of diseases characterized by inflamed muscles, and poses challenges for dermatologists due to its complexity in both diagnosis and treatment. 

The condition is characterized by distinctive skin findings, including a heliotrope rash around the eyes, Gottron papules over the joints, and facial erythema over the cheeks and nasal bridge. Muscular involvement often leads to weakness, particularly in the proximal muscles. 

Treating patients with dermatomyositis and related myositic disorders poses diagnostic and therapeutic challenges, and Dr Schlesinger comments that this condition, along with the broader category of myositic disorders, has not received sufficient attention. He looks forward to innovation in this area to improve approaches to diagnosis and treatment. 

Overlapping pathways 

Dr Schlesinger also emphasizes the overlapping inflammatory pathways that SCLE and dermatomyositis share with the more common dermatologic conditions, especially alopecia areata, atopic dermatitis, and psoriasis. 

With a focus on research, innovation, and collaborative efforts, dermatologists can work to address the diagnostic and therapeutic challenges associated with these rare diseases in dermatology.