Fever and rash

Contagious potential

Resuscitation

Rapid therapy

Diagnostic evaluation

Clinical setting

Severity of illness

Nature of rash

Petechial

Cellulitic

Vesiculobullous

Maculopapular

Emergent conditions presenting with fever and rash

Rapid recognition and therapeutic intervention are essential in certain diseases presenting with fever and rash to minimize as much as possible the associated morbidity and mortality. The major conditions involved include meningococcemia, Rocky Mountain spotted fever, staphylococcal toxic shock syndrome, streptococcal toxic shock-like syndrome, bacteremia or endocarditis with septic emboli, and the rapidly spreading cellulitis (Tables 17.2 and 17.3). All of these conditions can present with fever and rash in a fulminant, rapidly progressive form, requiring expedient therapeutic intervention, often on an empiric basis, before confirmation of the diagnosis, if the associated mortality rates are to be minimized.

Table 17.2 Approach to seriously ill patients with fever and rash

Clues	Disease	Diagnosis
Multiple purpuric lesions Earliest lesions small of back Rapid progression over hours	Meningococcemia	Gram stain of pustules Blood cultures
Tick exposure, headache, fever, rash 2nd–6th days Wrists, ankles, progressing to palms, soles, trunk	Rocky Mountain spotted fever	DFA of skin biopsy Serology (CF)
Fever, rash, hypotension, menstruating female using tampons Surgical wound or skin infection	Toxic shock syndrome	Isolation of phage group I staphylococci
Fever, rash, hypotension, rapid onset of organ dysfunction	Group A streptococcal toxic shock-like syndrome	Evidence of group A streptococcal infection
Elderly or immunocompromised patient Several lesions, macular to necrotic pustules	Bacteremia with septic emboli	Gram stain of pustules Blood cultures Gram stain of buffy coat
Painful spreading lesions Local trauma	Rapidly spreading cellulitis	Clinical

Abbreviations: DFA = direct fluorescent antibody; CF = complement fixation.

Table 17.3 Characteristics of serious rashes

Onset with or after fever

Petechial lesions

Rapid spread

Purpuric lesions

Palmar/plantar involvement

Generally, the most serious and rapidly progressive of these are associated with a petechial rash. These 1- to 2-mm purple lesions do not blanch with pressure, often coalesce to form larger ecchymotic areas, and usually are in the presence of leukocytosis and thrombocytopenia. Meningococcemia, Rocky Mountain spotted fever, and bacteremia/endocarditis with septic emboli are perhaps the most notable. However, other causes include gonococcemia, typhus, and rat-bite fever; viral infection, including dengue, hepatitis B, rubella, and Epstein–Barr virus (EBV); and noninfectious causes, including thrombotic thrombocytopenia purpura, Henoch–Schönlein purpura, vasculitis, and scurvy.

Rapidly progressive diseases with erythematous rash include staphylococcal toxic shock syndrome and streptococcal toxic shock-like syndrome, as well as the rapidly progressive cellulitis, which often have a vesicobullous component. In these conditions, as well as with necrotizing fasciitis, the patient often looks toxic out of proportion to the extent of the rash.

Meningococcemia

Of all the diseases presenting with fever and rash, meningococcemia is the one most likely to be rapidly fatal without early recognition and treatment. The ominous palpable purpura in an acutely ill, febrile patient characteristically suggests this disease. Other features that may be helpful in earlier diagnosis include sore throat, fever, muscle tenderness, and headache in the presence of significant leukocytosis and thrombocytopenia. The illness tends to occur in late winter and early spring and is well known to occur under crowded living conditions. The initial rash may be maculopapular, with the earliest petechial lesions occurring over pressure points such as the small of the back, and can easily be overlooked. The rash can progress rapidly over a few hours to the more classic, petechial form with peripheral acrocyanosis. Management requires immediate recognition, vigorous fluid replacement, and rapid therapy with aqueous penicillin or a third-generation cephalosporin, 12 to 24 million units daily intravenously (IV). Patients presenting with signs of adrenal insufficiency also require steroid replacement. The use of gamma globulin is controversial for patients with meningitis. Dexamethasone for 2 days started just before or with the first dose of antibiotics is indicated.