Vitiligo may be a complication of treatment for psoriasis. In one case study, a patient being treated with ixekizumab for psoriasis developed vitiligo, which may be due to the drug’s mechanism of action.
Vitiligo is an acquired depigmenting skin disorder characterized by melanocyte loss and low health-related quality of life. Psoriasis, another autoimmune skin disease, causes an itchy, scaly rash on the knees, elbows, trunk, and scalp. Notably, a 36-year-old male with a 32-year history of psoriasis was found to have developed vitiligo due to a specific treatment, ixekizumab.
The patient had no personal or family history of vitiligo, drug allergies, or any other autoimmune diseases. He was given a variety of treatments, but his widespread plaque psoriasis didn’t improve. Then, he was given ixekizumab, which appeared to improve his symptoms. But 11 months after treatment, even though his routine blood tests and autoimmune screen were normal, signs of vitiligo developed on his trunk, limbs, and face.
Ixekizumab is a monoclonal antibody that binds and inhibits IL-17A. We don’t fully understand how IL-17 inhibitors might induce vitiligo yet. One theory suggests that ixekizumab distorts the immune system, causing it to attack melanocytes. Furthermore, autoantigens induced by biologic therapy may cause autoantibodies to destroy melanocytes.
Several biologics used to treat psoriasis have been linked to vitiligo. This case is different from other published cases of vitiligo caused by ixekizumab because of the extent of the disease. In this case, the vitiligo was widespread and didn’t just affect the face, which hadn’t been observed before with ixekizumab.
Fortunately, new-onset vitiligo has a more favorable outcome than pre-existing vitiligo. Despite being offered phototherapy treatment for his vitiligo and a switch to anti-TNF treatment, the patient was kept on ixekizumab with no worsening of his vitiligo.
Source:
Pathmarajah, P., Benjamin-Laing, Z., Abdurrahman, M., Grunova, A., & Sinclair, C. (2022). Generalized vitiligo in a psoriatic patient treated with ixekizumab. Dermatol Ther, e15872. https://doi.org/10.1111/dth.15872
