Key Clinical Questions
What are the most common causes of fever and rash in the hospitalized patient?
What is the pathophysiology of fever and rash?
What other clinical symptoms and findings are associated with fever and rash?
How can laboratory tests help with diagnosis of the etiology of rash?
A 25-year-old graduate student who was living in student housing presented to the hospital complaining of a 4-day history of upper respiratory tract symptoms that have progressed to include fever and rash on his extremities. The rash began on his hands and feet as a pink, flat rash, but has progressed over the last several hours to be purplish in nature, and extends now to his trunk and face. He is admitted to your service for further evaluation and treatment.
The rapid progression of the patient’s rash and the appearance of macular rash that progressed to petechiae and purpura raised immediate concern for meningococcemia. The patient was placed in droplet precautions, blood cultures were collected, and ceftriaxone therapy initiated. Vital signs revealed blood pressure of 110/60, pulse rate of 118, respiratory rate of 24, and temperature of 39.2°C. No nuchal rigidity was noted. The patient’s respiratory status declined and he was admitted to the intensive care unit (ICU) and intubated. Blood cultures grew Neisseria meningitidis at 24 hours and laboratory findings were consistent with disseminated intravascular coagulation (DIC). A lumbar puncture was not performed due to severe thrombocytopenia. Multisystem organ failure developed rapidly.
The clinical presentation of patients with rash and fever must first be divided into categories of those who are critically ill versus those who are not. Critically ill patients with rash often have the fulminant onset of both fever and rash, and must be diagnosed quickly to receive appropriate care. The timing of the rash is important for judging the severity of the disease, with rapid onset often portending a more rapidly progressive course. The most worrisome cause of fulminant onset of rash is septicemia, especially purpura fulminans of meningococcemia, which can progress over hours or even minutes. Gradual or waxing and waning rash and fever suggest a more chronic process, or one that may be noninfectious, such as rheumatological disease or malignancy.
Patients presenting in the hospital with rash and fever must be divided into two categories: those who are critically ill and those who are not. Causes of critical illness include hemorrhagic fever, meningococcemia, Rocky Mountain spotted fever, toxic shock syndrome, Stevens-Johnson syndrome, toxic epidermal necrolysis, and acute vasculitis.
APPROACH TO FEVER AND RASH AT THE BEDSIDE
Some acute rash and fever syndromes are caused by infectious diseases that can be spread by airborne or respiratory droplets. Therefore, before beginning the history and physical, if such a transmissible disease is suggested, appropriate precautions should be instituted (Figure 88-1).