Case Report: Vitiligo and Alopecia Universalis Following Rituximab Therapy in a Patient with Myasthenia Gravis.

Rituximab, an anti-CD20 monoclonal antibody, is being used more frequently to treat refractory autoimmune disorders such as myasthenia gravis. While it is usually well tolerated, rare cases of paradoxical immune-mediated skin reactions have been rarely reported. However, the concurrent development of vitiligo and alopecia universalis following rituximab therapy has not been previously described. We report a rare case of simultaneous vitiligo and alopecia universalis developing during long-term treatment with rituximab in a patient with myasthenia gravis and discuss the clinical course and treatment response. This case report describes a 30-year-old woman with myasthenia gravis who developed vitiligo followed by alopecia universalis during a long term of Rituximab therapy. Cutaneous findings included well-demarcated depigmented patches on the trunks and bilateral arms and diffuse non-scarring alopecia affecting the scalp, eyebrows, eyelashes, and body hair, consistent with 100% score of Severity of Alopecia tool (SALT) indicating Alopecia universalis. Rituximab was discontinued due to a possible drug-reaction. Treatment with oral Baricitinib was initiated to target both vitiligo and alopecia universalis. Within three months, there was significant scalp hair regrowth and re-pigmentation of vitiligo patches with minimal adverse effects. This case highlights a unique temporal association of rituximab therapy and the simultaneous onset of vitiligo and alopecia universalis. Although the relationship between the drug and the onset of the skin diseases cannot be established, it is important to be aware of the possibility of immune-related skin adverse effects during rituximab therapy. Early intervention and the use of Janus kinase inhibitors, such as baricitinib, may lead to good clinical outcomes.