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Updated: Jul 18, 2026

Induction and Monitoring of Active Delayed Type Hypersensitivity (DTH) in Rats
Published on: July 19, 2007
Presumed dapsone-induced drug hypersensitivity syndrome causing reversible hypersensitivity myocarditis and
Rachael Y L Teo1, Yong-Kwang Tay, Chong-Hiok Tan
1Division of Dermatology, Changi General Hospital, Singapore.
Introduction:
A 22-year-old Malay soldier developed dapsone hypersensitivity syndrome 12 weeks after taking maloprim (dapsone 100 mg/pyrimethamine 12.5 mg) for anti-malarial prophylaxis.
Clinical Picture:
He presented with fever, rash, lymphadenopathy and multiple-organ involvement including serositis, hepatitis and thyroiditis. Subsequently, he developed congestive heart failure with a reduction in ejection fraction on echocardiogram, and serum cardiac enzyme elevation consistent with a hypersensitivity myocarditis.
Treatment:
Maloprim was discontinued and he was treated with steroids, diuretics and an angiotensin-converting-enzyme inhibitor.
Outcome:
He has made a complete recovery with resolution of thyroiditis and a return to normal ejection fraction 10 months after admission.
Conclusion:
In summary, we report a case of dapsone hypersensitivity syndrome with classical symptoms of fever, rash and multi-organ involvement including a rare manifestation of myocarditis. To our knowledge, this is the first case of dapsone-related hypersensitivity myocarditis not diagnosed in a post-mortem setting. As maloprim is widely used for malaria prophylaxis, clinicians need to be aware of this unusual but potentially serious association.
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