Classic childhood exanthems by viral pattern — measles, rubella, roseola, fifth disease, hand-foot-mouth, varicella.
| Disease | Agent | Classic features | Management |
|---|---|---|---|
| Measles (rubeola) | Paramyxovirus | 3 C's (cough, coryza, conjunctivitis) + KOPLIK spots (white lesions on buccal mucosa) → cephalocaudal maculopapular rash. Highly contagious | Supportive + vitamin A; airborne isolation. Complications: pneumonia (#1 cause of death), encephalitis, SSPE years later |
| Rubella (German measles) | Togavirus | Mild fever + posterior auricular/occipital LAD + face-down rash. Congenital rubella: cataracts, deafness, PDA | Supportive; avoid in pregnancy |
| Roseola (sixth disease) | HHV-6 | Infant 6 mo–2 yr; high fever 3–5 days → fever defervesces THEN rash appears on trunk | Supportive. Most common cause of febrile seizures |
| Erythema infectiosum (fifth disease) | Parvovirus B19 | 'Slapped cheek' rash → lacy reticular on extremities. Aplastic crisis in sickle cell; hydrops fetalis | Supportive; avoid pregnant women |
| Hand-foot-mouth | Coxsackie A | Vesicles on palms, soles, oral mucosa; fever | Supportive |
| Varicella (chickenpox) | VZV | Crops of vesicles in DIFFERENT stages (macule → papule → vesicle → crust) | Acyclovir for adolescents/adults/immunocompromised; airborne + contact isolation |
| Scarlet fever | Group A Strep | Sandpaper rash + strawberry tongue + circumoral pallor + Pastia lines (axillary). After strep pharyngitis | Penicillin/amoxicillin × 10 days |
| Kawasaki | Vasculitis (not viral) | ≥5 days fever + ≥4 of: conjunctivitis, mucositis (strawberry tongue), rash, extremity changes (palmar erythema/desquamation), cervical LAD | IVIG + high-dose aspirin within 10 d; echo to monitor coronary aneurysms |