Cutaneous Adverse Reactions Associated with Monoclonal Antibodies Treatment in Multiple Sclerosis: Case Reports and Short Literature Review

Background and aims. Multiple sclerosis is a disease of the central nervous system, whose treatment often involves the use of monoclonal antibodies. This can lead to a series of complications that the clinician should pay attention to and accordingly adjust the therapy. We aim to emphasize real-life experiences with adverse cutaneous reactions to monoclonal antibodies by presenting a series of two cases from our clinic. Methods. In the first case, a female patient was treated with natalizumab for eight years and developed relapsing-remitting cutaneous lesions following the monthly administration of the treatment. The second case is of a male patient treated with ocrelizumab, who developed plaque-like lesions following the fifth administration. We analyzed the biological parameters and performed investigations, dermatological evaluation and skin biopsies. Results. The result of the skin biopsy for the natalizumab patient showed a chronic spongiotic dermatitis, with the anti-natalizumab antibodies being negative. The patient who received ocrelizumab developed nummular eczema, disseminated on his trunk and limbs. Conclusions. Given the fact that these therapies are frequently used in multiple sclerosis patients, and their skin adverse reactions are known, we described some particularities and a brief review of the literature with practical implications. Further studies need to be conducted to establish a firm association between monoclonal antibodies therapy and adverse cutaneous reactions, but the clinician should be aware of their existence.