Les fièvres périodiques ou fièvres inflammatoires héréditaires sont caractérisées par des accès inflammatoires intermittents. Plusieurs entités sont actuellement identifiées dont la fièvre méditerranéenne familiale (FMF) et le syndrome d’hyper-immunoglobulines D (hyper IgD). Nous rapportons le cas d’un enfant âgé de 6 ans qui présentait depuis un an des pleuropneumopathies fébriles récidivantes, à bascule, associées à des douleurs thoraciques et une élévation permanente des IgD. L’origine ethnique et le tableau clinique et radiologique étaient en faveur d’une FMF associée à une élévation des IgD et non d’un authentique syndrome d’hyperIgD ; malgré l’absence d’amélioration sous colchicine et l’absence des principales mutations rencontrées lors de la FMF.

Periodic fever or hereditary inflammatory fevers are characterized by intermittent inflammatory attacks. Many entities are well recognized today such as familial mediterranean fever (FMF) and hyperimmunoglobulinemia D syndrome (HIDS). We report on the case of a 6-year-old boy referred for evaluation of a recurrent fever associated with chest pain, pneumonitis, or pleuritis since the age of 5 years. Laboratory data showed leukocytosis, a high erythrocyte sedimentation rate, and C-reactive protein; however, a permanent high serum level IgD was noted. Stereotypical episodes of fever appeared every 4–6 weeks, while infectious, malignant, and auto-immune causes were eliminated. A search for the most common mutations of the FMF gene in Tunisian patients (M694V, M680I, V726A, E148Q, M694I, and A744S) were negative. Likewise, urinary leukotriene E(4), which may be increased in HIDS, was normal in this patient. Mevalonate kinase activity in lymphocytes was not assayed. Ethnic origin and clinical presentation suggest FMF with an increased IgD rather than authentic HIDS, in spite of the lack of improvement under colchicine treatment and the negativity of the main mutations involved in FMF.