Morphea is a chronic immune-mediated fibrosing disorder characterized by excessive collagen deposition in the skin. Linear morphea of the scalp (en coup de sabre) commonly demonstrates the Koebner phenomenon, wherein lesions develop at sites of trauma; however, the reverse Koebner phenomenon—trauma-induced regression—is exceptionally rare. We report an unusual case of linear scalp morphea showing early regression following a diagnostic punch biopsy. A 71-year-old male presented with an asymptomatic, indurated linear plaque on the scalp of two months’ duration. Histopathology from a 3.5-mm punch biopsy confirmed morphea, demonstrating dense collagen bundles with lymphoplasmacytic infiltrate. At follow-up eight days after the procedure, the lesion showed marked softening, reduction in linear extent, and reappearance of follicular openings adjacent to the biopsy site. Given the brief and non-antifibrotic nature of post-procedural therapy, the improvement was unlikely to be pharmacological. We hypothesize that localized trauma disrupted the Th2-driven profibrotic microenvironment, potentially activating matrix metalloproteinases and initiating early collagen remodeling. While reverse Koebner responses have been described in psoriasis, vitiligo, and cutaneous lymphomas, this phenomenon is virtually unreported in morphea. This observation suggests that controlled cutaneous injury may modulate fibrotic activity in select cases of localized scleroderma and merits further investigation.
Gowda et al. (Thu,) studied this question.