Organ Involvement and Treatment Response across Cutaneous Sarcoidosis Subtypes.

Cutaneous sarcoidosis presents with diverse morphologies, yet comparative data on systemic involvement, disease course and treatment response across subtypes remain limited. We conducted a 2-centre cross-sectional study including patients with histologically confirmed sarcoidosis identified through ICD codes, stratified into patients with and without cutaneous involvement and further by cutaneous subtype. Demographics, extracutaneous organ involvement, treatment response, clinical course and the organ leading to initial diagnosis were analysed. Among 125 patients (median age 53 years; 57% female), 99 had cutaneous sarcoidosis and 26 had no skin involvement. All major subtypes of cutaneous sarcoidosis were represented: plaque (39), papular (19), scar (15), subcutaneous (13) and lupus pernio (4); erythema nodosum (9) represented acute disease. Papular sarcoidosis (19) showed the mildest systemic involvement. Lymph nodes (64%) and lungs (48%) were most frequently affected with subtype specific variation. Skin lesions led to diagnosis in 78% of cases. Remission with topical therapy was rare (11%), whereas systemic glucocorticoids (21%) and other immunosuppressants (37%) showed higher response rates; sirolimus (11%), hydroxychloroquine (10%) and TNF inhibitors (8%) were most effective. Relapse occurred in 40% and 46% required long-term systemic therapy. Cutaneous sarcoidosis subtypes differ markedly in systemic involvement, treatment response and disease course, supporting biological heterogeneity and the need for individualized management.