Histopathological and immunohistochemical features of facial papules in frontal fibrosing alopecia.
Facial papules (FPs) are considered to be created by the inflammatory process involving facial vellus hairs in frontal fibrosing alopecia (FFA).This study aimed to demonstrate the histopathological features of FPs and the composition of the inflammatory infiltrate.Eighteen patients with FPs of FFA were enrolled in the study after histopathological confirmation. Histopathological evaluation of the specimens was performed by two dermatopathologists. The samples were immunostained with CD4, CD8, CD123 monoclonal antibodies. The percentage and proportion of cells stained with these markers were investigated.Follicular lichenoid reaction and perifollicular fibrosis were present in all cases. Vellus hairs were detected in 83.3% of biopsy specimens (15 cases), all of them were involved by the inflammation. The Majority of follicles (72%) revealed follicular plugs. Elastic fibers reduction and destruction occurred in the papillary dermis of 78% and the perifollicular dermis (adventitial dermis) of all the specimens. Prominent sebaceous glands were detected in 78% and had dilated duct in 72% of samples. CD4+ T cells formed 67.72% and CD8+ T cells 32.28% of the infiltrate. The mean CD4/CD8 ratio was 2.48. In 13 (72.2%) biopsy specimens <10% of the infiltrate was positive for CD123 marker.Perifollicular inflammation, fibrosis, and elastic fibers destruction were constant histopathological features of FPs; furthermore, prominent sebaceous glands were present in the majority of samples. We also observed a CD4+predominance in the infiltrate.
Authors: A Rakhshan, N Momenpour, S Dadkhahfar, M Gheisari