Acne vulgaris and rosacea and their variants are easily identified by dermatologists; bacterial folliculitis and Pityrosporum folliculitis have extra-facial involvement and are relatively easy to suspect. Both EF and FM may be missed upon initial evaluation.

EF in adults has two clinical presentations with only slight overlap. In one, usually idiopathic, lesions are limited to the face and may be uniformly pustular, hence the term “eosinophilic pustular folliculitis” as reported initially by Ofuji and later in the pediatric literature. In the other, often associated with immune deficiencies including HIV infection, lesions involve the trunk , especially the back. In the setting of HIV infection, lesions are similar to the so-called papular eruption of HIV disease. In both presentations, annular plaques with peripheral pustules may be seen. In some patients, annular plaques with pustules are uniformly seen.

FM may be primary or secondary to other cutaneous disorders including mycosis fungoides. Papules of both primary and secondary FM are only faintly reddish, edematous, sometimes boggy, and often confluent into plaques with pea d’orange surface appearance. Lesions in hairy areas are usually alopecic (alopecia mucinosa). Non-facial lesions may be seen in primary and secondary FM, both of which may also have scaly patches or plaques.