Effective treatment by glycolic acid peeling for cutaneous manifestation of familial generalized acanthosis nigricans caused by FGFR3 mutation

Background Acanthosis nigricans (AN) can occur as a cutaneous manifestation of genetic diseases, one of which is associated with activating mutations of the fibroblast growth factor receptor 3 gene (FGFR3). Objective We explored familial AN patients with FGFR3 mutations and examined the effectiveness of glycolic acid (GA) peeling in improving their skin manifestations. Methods Sanger sequencing was performed for the genomic DNA extracted from leucocytes of the family members involving familial AN. GA peeling was carried out for the two patients of familial AN once every 2 weeks. Results Heterozygous c.1949A>C (p.K650T) mutation in FGFR3 was identified for the affected family members examined, whereas the wild-type sequence was found for two unaffected individuals. Hyperpigmentation and coarseness of the skin were improved by GA peeling at regular intervals with few adverse effects. Conclusion We diagnosed our cases as familial generalized AN caused by heterozygous c.1949A>C (p.K650T) mutation of FGFR3. We propose that GA peeling is a useful and safe therapeutic option to treat familial AN.