The spectrum of signs and symptoms of 645 consecutive children diagnosed from 1984 to 1996 with boutonneuse fever (BF), a mild rickettsial disease caused by Rickettsia conorii endemic in the Mediterranean basin, are reported. The major clinical features were fever (97.2%), exanthema (96.1%) and "tache noire" (71.8%). The large series examined permitted the authors to observe some rare or disregarded clinical features of the disease: cases with papulovesicular exanthema, reported previously only in adults who had been infected by R. conorii in Africa; and cases in which the only symptom was an isolated lymphadenopathy.
Conclusion: R. conorii infection should be considered in patients with lymphadenopathy who live in or have travelled to an endemic area, even when other, more specific features, are not present. Also pox-like vesicular lesions may be caused by this organism, awaiting confirmation by using culture techniques instead of serology. The serological confirmation of BF by immuno fluorescent antibody test is possible only late in the illness.