Keratosis follicularis spinulosa decalvans X-linked (KFSDX) is part of the spectrum of a rare disorder known as keratosis pilaris atrophicans. Here, we report the case of a 14-year-old boy who presented with a history of abnormal hair since birth. He also had a history of skin lesions and hair loss. There was no similar condition in the family, and the parents were not consanguine. Scalp examination revealed woolly hair, a solitary scarring alopecia patch, and follicular papules. There were also patches of scarring alopecia on the lateral portion of the eyebrows and whole eyelashes bilaterally. His nose showed multiple, skin-colored, non-scaly follicular papules. The differential diagnosis included lichen planopilaris, Graham Little-PiccardiLassueur syndrome, KFSDX, keratosis follicularis spinulosa decalvans, and structural hair anomalies. Hair examination under light microscopy was normal. Skin biopsy from the follicular papule on the nose revealed follicular plugging with normal epidermis and dermis. Based on the above clinicopathological findings, the patient was diagnosed with KFSDX associated with woolly hair. He was reassured, but he did not show up for further treatment during the follow-up.
