Background. Rapp-Hodgkin syndrome is a rare genetic disease from the ectodermal dysplasia group. It manifests with damage of ectodermal structures — layer of embrional tissue that provides the development of many organs and tissues in the body, such as: skin, sweat glands, hair, teeth, and nails. Disease symptoms may range from mild to severe and include dental abnormalities, fragile, thin or no hair, abnormal nails, hypohidrosis (due to the reduced number of sweat glands), cleft lips and palate. Hidradenitis suppurativa is a chronic inflammatory disease that predominantly affects apocrine glands areas. This nosology is characterized by painful nodes, abscesses, and fistulas, prone to relapses and leading to scarring.Clinical case description. The authors present a clinical case demonstrating the combination of Rapp-Hodgkin syndrome and severe hidradenitis suppurativa in 17-year-old male patient.Conclusion. The heterogeneous clinical findings of hidradenitis suppurativa and history of rare genetic disease result in patients' admissions to various medical specialists. Thus, it leads to delayed verification of the diagnosis and incorrect treatment methods. As a result, patients have persistent cosmetic skin defects, possible complications of irrational treatment, and decreased quality of life by the time of diagnosis.