SG01 Naltrexone: not a one-trick pony for opioid overdose. The use of naltrexone to successfully treat severe Hailey–Hailey disease

Abstract A 65-year-old man presented with a 3-year history of burning, itching and splitting of the scrotal skin. He had previously been treated with topical corticosteroids, emollients, antifungals and multiple short and long courses of antibiotics, with limited response. A biopsy was performed, which confirmed a diagnosis of Hailey–Hailey disease (HHD). HHD is an autosomal dominant genodermatosis characterized by vesicles that form eroded, erythematous plaques with painful rhagades in flexural areas. Oral naltrexone has been used to treat alcohol use disorders and opioid overdose for many years. Naltrexone is known to partially block opioid receptors and indirectly antagonizes Toll-like receptor 4 in the microglial cells of the central nervous system and peripheral macrophages. This potentially reduces inflammation due to a decrease in the production of substance P, tumour necrosis factor, interleukin-6 and other proinflammatory cytokines. In 2022, acitretin was commenced and uptitrated to 25 mg once daily. Unfortunately, the patient’s condition deteriorated with extensive erosions affecting the groin and scrotum. A surgical opinion was sought and was futile. Courses of prednisolone did not help. Other immunosuppressive agents such as methotrexate, ciclosporin and azathioprine have been described in the literature with varying efficacy. After 2 years, the pain from his erosions had reduced his ability to walk. Naltrexone 2.5 mg was commenced and subsequently uptitrated to 5 mg. Six weeks later, the patient had an 80% improvement in his condition. The patient experiences no side-effects from the treatment and requires no blood monitoring. This man with severe HHD predominantly effecting the scrotum was commenced on oral naltrexone. Naltrexone is postulated to work due to analgesic and anti-inflammatory effects. It is a well-tolerated treatment for severe HHD that has drastically improved both our patient’s skin and his quality of life.