Iatrogenic Corticosteroid Atrophy Mimicking Bilateral Morphea en Coup de Sabre: A Case Report

Background: Corticosteroids affect numerous downstream cytokines to exert anti-inflammatory and immunosuppressive effects. Intralesional corticosteroid injection provides several advantages, including bypassing the stratum corneum to deliver a higher concentration of drug locally, while reducing systemic exposure. Intralesional corticosteroids are used in a variety of dermatologic conditions, and suboccipital steroid injection has been described as a novel treatment for cluster headaches.

Case Presentation: A 52-year-old Caucasian female presented to the outpatient dermatologic clinic with indented skin lesions on the scalp and forehead for six weeks. The indentation started on her left frontal scalp and spread down gradually to her forehead and temple. She later noticed the same indentation appearing on her right side. She reported severe pain and the “worst headache” before the lesions started, but there was no further pain after the lesions appeared.

Dermatologic examination demonstrated two symmetric hypopigmented linear atrophic plaques extending from the lateral forehead to the frontoparietal scalp on each side.

A punch biopsy from the left superior central forehead showed epidermal atrophy with compact orthokeratosis, and scattered telangiectasias within the papillary dermis. Elastin van Giesonstaining demonstrated a loss of elastic fibers in the papillary dermis. There was no dermal sclerosis. The adnexal structures, CD34 expression, and the elastic component of the reticular dermis were intact. Direct immunofluorescence studies were negative.

Upon further questioning, the patient revealed that she had injections with an unknown medication to the occipital and frontal scalps due to severe headaches from a motor vehicle accident. A diagnosis of steroid-induced skin atrophy was made from clinicopathologic correlation.

Conclusions: The adverse effects related to intralesional corticosteroid injections include hypopigmentation, telangiectasias, striae, and atrophy of the skin and subcutaneous fat. When present on the frontal and temporal scalp, atrophic plaques can mimic morphea en coup de sabre, a form of linear localized scleroderma with an autoimmune etiology. Several cases of bilateral morphea en coup de sabre have been previously reported. This case study highlights the importance of obtaining a comprehensive patient history in formation of a differential diagnosis. It also showcases the potential complications of intralesional corticosteroid injections, emphasizing the informed consent process for patients to fully understand possible adverse effects from treatment.