Evaluating the febrile patient with a rash

The differential diagnosis for febrile patients with a rash is extensive, D iseases that present with fever and rash are usually classified according t o the morphology of the primary lesion. Rashes can be categorized as maculo papular (centrally and peripherally distributed), petechial, diffusely eryt hematous with desquamation, vesiculobullous-pustular and nodular, Potential causes include viruses, bacteria, spirochetes, rickettsiae, medications an d rheumatologic diseases, A thorough history and a careful physical examina tion are essential to making a correct diagnosis, Although laboratory studi es can be useful in confirming the diagnosis, test results often are not av ailable immediately. Because the severity of these illnesses can vary from minor (roseola) to life-threatening (meningococcemia), the family physician must make prompt management decisions regarding empiric therapy. Hospitali zation, isolation and antimicrobial therapy often must be considered when a patient presents with fever and a rash.