Severe skin reactions associated with cladribine in people with multiple sclerosis

Objective: To report three cases of severe skin reactions in patients treated with cladribine for multiple sclerosis. Methods: Case study. Results: Patients developed severe rash 3-192 days after receiving cladribine. All were effectively treated with steroids and antihistamines. Additional doses of cladribine were administered after pretreatment with steroids and anti-histamines. One patient developed mild recurrence following re-exposure, which resolved within three days, whilst another patient tolerated re-exposure without further adverse reaction. Conclusion: Severe skin reactions, well described in patients receiving cladribine for treatment of haematological conditions, may occur in patients treated with this compound for multiple sclerosis. Neurologists need to be aware of this rare, but significant adverse reaction. Re-exposure may be safe with standard pre-treatment against allergic reactions.