Pseudolymphomatous Folliculitis: A Distinctive Cutaneous Lymphoid Hyperplasia
A 45-year-old married male presented to us with a red raised lesion on the right side of forehead. The lesion has started 2 months back as single papule and gradually progressed to present size. Recently, he also noticed development of new papules around it and some pustules on it []. There was no history of any drug intake, insect bite or any local trauma prior to lesions. Before presenting to us, patient was treated with various topical and oral antibiotics like amoxicillin-clavulanic acid combination, azithromycin and linezolid etc., but lesions kept on increasing without any improvement.\nCutaneous examination erythematous indurated minimally tender plaque of 2 cm × 4 cm on the right side of the forehead topped with few pustules and brownish crust at places. Furthermore, there were two discrete erythematous papules of recent onset developing around it. There was no any lymph node swelling noted. Rest of his cutaneous and systemic examination was unremarkable. Ophthalmic examination revealed no abnormality.\nA diagnosis of fixed cutaneous leishmaniasis, deep fungal infection and pseudolymphoma was thought. Pus swab from lesion showed no growth. A biopsy of the lesion revealed dense lymphocytic infiltrate extending from upper dermis to lower dermis []. Involvement of subcutis was not seen. Infiltrate also contained numerous histiocytes, few neutrophils and occasional plasma cells that surrounded and infiltrated hypertrophic hair follicles with dilated sebaceous glands (so called activated pilosebaceous units). Some lymphocytes infiltrated into the hair follicles leading to its destruction and ultimately effacement by infiltrate []. Infiltrated cells were medium to large sized lymphocytes with hyperchromatic nuclei, high nuclear/cytoplasmic ratio, and prominent nucleoli accompanied by numerous histiocytes, netrophils, and few plasma cells []. No any bacterial or fungal elements were identified. On clinicopathological correlation a diagnosis of PLF was made. Due to economic constraints, immunohistochemistry for T- and B-cell markers or cluster designation 1a could not be done. Patient was advised topical clobetasol and fusidic acid combination in a cream form. Also oral prednisolone 40 mg per day with antacids and oral calcium supplement which was tapered over 40 days. Intra-lesional triamcinolone injection (20 mg/ml) was given after 7 days of starting oral steroids. Remarkable improvement was seen after 4 days of single injection [].