Scarring Alopecia of the Scalp as the Revealing Manifestation of Systemic Sarcoidosis: A Case Report

Abstract

Aims: To report an exceptional case of scalp sarcoidosis revealing systemic sarcoidosis and to underline the contribution of trichoscopy to the diagnosis. Presentation of Case: A 50-year-old Moroccan woman with multinodular goitre presented with a chronic, non-pruritic, painless alopecic plaque of the scalp that had been evolving since 2006, without systemic symptoms. Examination showed an erythematous alopecic plaque of the left parieto-temporal region, crusted in places, measuring 6 × 7 cm, with a negative pull test. Trichoscopy (DermLite DL4) revealed multiple yellow-orange areas, tortuous and arborizing vessels, whitish scarring areas, and white peripilar scales. Scalp biopsy showed multiple epithelioid and giant-cell granulomas without caseous necrosis, confirming sarcoidosis; direct immunofluorescence was negative. Systemic work-up showed an angiotensin-converting enzyme level at the upper limit of normal and stage II thoracic sarcoidosis. The patient received an oral corticosteroid minipulse, hydroxychloroquine, and a very potent topical corticosteroid; the orange trichoscopic features regressed, but no hair regrowth occurred. Discussion: Scalp sarcoidosis is rare and most often presents as scarring alopecia. Trichoscopy can provide diagnostic clues, particularly yellow-orange areas and arborising vessels, while histopathological examination remains necessary for confirmation. Scalp involvement may be associated with systemic, particularly pulmonary, disease and therefore warrants systemic evaluation. Conclusion: Scalp sarcoidosis, although rare, should be recognised because it frequently accompanies systemic disease, and early diagnosis may prevent irreversible follicular destruction.