Polymethyl-Methacrylate Hypersensitivity with Associated Folliculitis Decalvans After Cranioplasty: A Case Report.

Polymethyl methacrylate (PMMA) has been routinely used as bone cement, being well tolerated by most patients. The authors report the case of a 42-year-old patient that underwent cranioplasty with PMMA prosthesis, that reported progressive and persistent skin symptoms starting 45 days after surgery. Dermatologic evaluation revealed an extensive reddish scar plaque, associated with polytrichia and alopecia, located only in the left parieto-occipital region, above the PMMA cranioplasty. Scalp biopsy and bone cement specific patch test revealed both folliculitis decalvans (FD) and weak PMMA hypersensitivity. The patient was managed with dapsone for FD, and graft removal was not necessary. This is the second case of post-cranioplasty PMMA hypersensitivity, and the first report of potential contact dermatitis induced FD.