Folliculitis decalvans: a case report of satisfactory recovery after implementing isotretinoin therapy

Introduction: Folliculitis decalvans is a rare skin disease characterized by the presence of painful papules and pustules with an underlying neutrophilic infiltrate, usually on the scalp. Its treatment is lengthy and challenging, and recurrence is relatively common. Although its etiology is unknown, several theories explaining its development have been proposed, including colonization by Staphylococcus aureus. Case description: This is the case of a 26-year-old male healthcare worker who visited the outpatient service after experiencing a 4-year history of painful pustules on the scalp; initially these lesions were located in the occipital region, but then also started to appear in the temporal and parietal regions. After being treated for bacterial folliculitis and having several recurrences, a skin biopsy was performed, which allowed diagnosing him with folliculitis decalvans. Once the diagnosis was made, isotretinoin (20mg) treatment was implemented for a year and a half, achieving complete remission of the lesions. Conclusion: Although this case has some limitations, such as the lack of histopathology images and some control laboratory tests, it clearly shows the difficulties faced when treating this type of skin disorders and presents an overview of the use of isotretinoin, evidencing that although this drug is well tolerated, possible adverse reactions from drug interactions with trimethoprim/sulfamethoxazole may arise. In addition, this case is of great importance since the possible presence of a familial cluster of folliculitis decalvans could be confirmed, if further genetic testing is performed.