Differential diagnoses of pseudolymphomatous folliculitis: considerations as regards one case.

Pseudolymphomatous folliculitis (PLF) is a rare disease of cutaneous lymphoid hyperplasia, with a low index of clinical suspicion. We present the clinical case of a 19-year-old male patient, with a solitary violet erythematous nodule of 6 months of evolution, located in the right infraorbital region, without presenting another symptomatology. Histopathological examination showed a lymphocytic infiltrate that surrounds the hair follicles, sebaceous and sweat glands that focally destroy their basement membrane. PLF was diagnosed based on histological and immunohistochemical studies. In the multiple studies and case reports, the variability of the initial clinical diagnosis never corresponds to PLF, becoming a pathology with a low suspect index.