[Severe drug hypersensitivity reaction (DRESS syndrome) to doxycycline]

Background: While many cases of DRESS reaction to minocycline have been described, few of these involve doxycycline.

Case study: A 59-year-old woman of African origin was repatriated after a journey to Ghana for hyperthermia with infiltrated maculopapular exanthema, facial oedema (no mucosal involvement) and polyadenopathy. Laboratory tests revealed hypereosinophilia, hepatic cytolysis and mononucleosis syndrome. Cutaneous histology was non-specific. The patient had been taking doxycycline as antimalarial prophylaxis for three weeks before the onset of symptoms. DRESS to doxycycline was diagnosed. Patch-tests with doxycycline three months later proved negative. The patient's HLA phenotype was A3/A30 and B39/B42.

Discussion: An intrinsic causal relationship with doxycycline was likely in this case (I3). Although patch-test sensitivity and specificity with doxycycline remains unknown in DRESS exploration, a negative result does not necessarily rule out the diagnosis. A number of cases of DRESS to doxycycline have been described recently, possibly as a result of more frequent prescription (malarial prophylaxis, acne). Subjects of African ethnicity or having specific HLA phenotypes are at higher risk of developing drug hypersensitivity.

Conclusion: This patient is the third case of DRESS to doxycycline described in the literature. The originality of this case lies in the allergological investigation using patch-tests and HLA determination.