ALA-iPDT for follicular occlusion tetrad concomitant with pachyonychia congenital type II and ankylosing spondylitis

The follicular occlusion tetrad is a complex dermatologic syndrome which can concomitant with other diseases. The case reported a young male patient suffer from follicular occlusion tetrad (acne conglobata, hidradenitis suppurativa, dissecting cellulitis of the scalp, and pilonidal sinuses) concomitant with pachyonychia congenital type II (thickened nails, palmoplantar keratoderma, multiple cysts) and ankylosing spondylitis (lumbago, human leukocyte antigen-B27 positive). The genetic analysis showed the KRT17 gene mutation on exon 1 (c.T284C) supports the diagnosis. Whereupon, a comprehensive therapy scheme of 5-aminolevulinic acid-mediated interstitial photodynamic therapy (ALA-iPDT) combined with surgery offered excellent response. This case reports a rare condition and proposes a therapeutic option that may work.