Exanthems

exanthem: means a skin eruption that bursts forth or blooms

•	think bacteria, virus, or drug

•	examine lymph nodes on PE (helps ddx)

•	ddx for all = viral exanthem NOS, drug eruption, scarlet fever

Childhood Exanthems:

1st disease: measles

2nd disease: scarlet fever(only bacteria of the six)

3rd disease: rubella (3 day measles)

4th disease: Duke's disease (no longer believed to exist, may have been coxsackie virus or echovirus)

5th disease: erythema infectiosum

6th disease: roseola infantum

•	Hand, foot, and mouth disease

•	Infectious Mononucleosis

•	Kawasaki Disease

•	Gianotti-Crosti syndrome

•	Unilateral Laterothoracic Exanthem

Enteroviruses = echovirus and coxsackiviridae

•	= most common viral exanthem

•	roseola, erythema infectiosum = relatively common

•	measles, German measles, scarlet fever = uncommon

•	nonspecific exanthem with non-specific viral systemic symptoms (ask about N/V/D i.e. entero)

•	in most cases one must be satisfied with the diagnosis of “viral exanthem”.

drug vs. infectious:

•	drug – suddenly without prodrome (“drug red”)

•	infectious – often with prodrome

QUIZ/COMPARISON OF FEATURES OF EACH DISEASE:

pharyngitis (sore throat) is a prominent feature of: scarlet fever (but NOT Kawasaki), infectious mononucleosis

conjunctivitis is a prominent feature of: Kawasaki disease, measles

enanthems:

hand,foot, and mouth disease 90%; apthae-like erosions, small and asymptomatic

measles Koplik's spots - on buccal mucosa, opposite pre-molar teeth

scarlet fever strawberry tongue, entire oral cavity may be red

Kawasaki disease strawberry tongue and cherry red lips with fissuring and crusting (though no sore throat vs. scarlet fever)

lymphadenopathy:

roseola infantum suboccipital lymphadenopathy

infectious mononucleosis cervical or generalized lymphandenopathy

rubella postauricular, suboccipital, cervical

Kawasaki disease cervical lymphadenopathy (often a single node)

SUMMARY

Exanthem:

Characteristics:

erythema infectiosum

slapped cheeks; fish-net like eruption

measles

the 4 C’s; cephalocaudal spread

rubella

cephalocaudal; light pink and discrete; LAN

scarlet fever

circumoral pallor; strawberry tongue; sandpaper rash; Pastia’s lines; post rash desquamation with Beau’s lines

roseola infantum

look too well for fever 103-106°; rash after fever breaks

Any Age:

•

AGEP

•	pityriasis rosea

•	HIV seroconversion

•	SLE (generalized ACLE presents as widespread morbilliform or exanthematous eruption often focused over the extensor aspects of the arms and hands and characteristically sparing the knuckles)