The Dapsone Hypersensitivity Syndrome revisited: a potentially fatal multisystem disorder with prominent hepatopulmonary manifestations

Dapsone has been used for many indications because of its antibiotic and anti-inflammatory effects [1]. Not only has it been the drug of choice for the treatment of leprosy (Hansen's disease) since the middle of the 20th century, but it has also been used for the treatment of brown recluse spider bite [1,2], dermatitis herpetiformis, vesicobullous dermatoses, cutaneous vasculitis, polyarteritis nodosa, nodulocystic acne, cutaneous mycetoma and multiples other dermatologic indications all of which may be seen as manifestations in certain occupational diseases [1]. Since the advent of the era of the Acquired Immunodeficiency Syndrome (AIDS), dapsone has been increasingly utilized in the chemoprophylaxis of Pneumocystis carinii infection in combination with Trimethoprim/Sulfamethoxazole. This has led to increasing incidence of dapsone-related complications. Table 1 lists the multiple adverse effects of Dapsone, including the dapsone hypersensitivity syndrome (DHS) and DRESS syndrome. Hemolysis (more likely to occur with deficiency of glucose 6-phosphate dehydrogenase or G6-PD), bone marrow aplasia, renal disease, peripheral neuropathy, methemoglobinemia, nausea, dizziness, fatigue and other systemic manifestations may occur singly or in combination in patients on dapsone therapy. Of these, DHS is characterized by the onset of fever, skin eruption and internal organ involvement several weeks to as late as 6 months after patients are given this drug. Untreated the syndrome can lead to severe organ dysfunction and even death. The definitive mechanism for DHS is unclear, but it is hypothesized that it is mediated by immune activation and elaboration of inflammatory cytokines. This case report emphasizes the pulmonary effects associated with DHS. The following sections provide an overview of the presentations, pathogenesis, diagnosis and management of DHS.A twenty-one-year old previously healthy nursing student, with no significant past medical or surgical history, presente