Sebaceous gland atrophy in seborrheic dermatitis of the scalp; a pilot study

Sebaceous gland (SG) atrophy is well-documented in scalp lesions of psoriasis and has been considered as an important clue to psoriatic alopecia. However, its specificity for psoriasis has been questioned over the years. We hypothesize that SG atrophy is not specific for psoriasis and looked for its presence in biopsies of seborrheic dermatitis of the scalp.We conducted a retrospective study of biopsy specimens of clinically suspected and histopathologically proven seborrheic dermatitis of the scalp for changes in SGs between January 1, 2014 and August 6, 2021.SGs lobules were smaller and narrower in five of the six cases of seborrheic dermatitis, and SG atrophy was present in four out of six cases.SG atrophy is observed in seborrheic dermatitis and is not specific for psoriasis or psoriatic alopecia.