| Disease | Pathogen | Classic Presentation & Buzzwords |
|---|---|---|
| Measles | Measles virus | 4 C’s (Cough, Coryza, Conjunctivitis, Koplik spots). Rash: Face Body (Confluent). Assoc: Vitamin A deficiency. |
| Rubella | Rubella virus | Post-auricular LAD. Rash: Face Body (spares 3 days, non-confluent). Assoc: Congenital (PDA, cataracts, deaf), Adult arthritis. |
| Roseola | HHV-6 | High fever breaks Rash appears. Rash: Trunk Face. Assoc: Febrile seizures. |
| Fifth Disease | Parvovirus B19 | ”Slapped Cheek” Lacy/Reticular body rash. Assoc: Aplastic crisis (Sickle Cell), Hydrops fetalis. |
| Varicella | VZV | ”Dewdrop on a rose petal”. Lesions in different stages of healing. t Rash: Trunk Extremities. |
| Scarlet Fever | Strep pyogenes | Sandpaper rash, Strawberry tongue, Circumoral pallor. Assoc: Strep throat, Desquamation (palms/soles). |
Fever-rash relationship
- Measles (Rubeola): Fever first (with cough, coryza, conjunctivitis) → Rash appears 3-5 days later, spreading from head to toe.
- Rubella (German Measles): Low-grade fever → Rash appears 1-2 days later, spreading quickly from head to toe.
- Scarlet Fever: Fever and sore throat begin together → “Sandpaper” rash appears 1-2 days later.
- Erythema Infectiosum (Fifth): Low-grade fever/prodrome resolves → “Slapped cheek” rash appears days later.
- Roseola Infantum (Sixth): High fever for 3-5 days → Fever breaks → Rash appears after the fever is gone.
- Varicella (Chickenpox): Fever and vesicular rash appear at the same time (lesions in various stages).