Oral lesions in viral exanthems
Oral lesions in viral exanthems
🔹 Oral Lesions in Viral Exanthems
| Viral Illness | Oral Lesion | Key Features |
|---|---|---|
| Rubella (German measles) | Forchheimer spots | Small, red petechial spots on soft palate; may precede or accompany rash |
| Measles (Rubeola) | Koplik spots | Bluish-white spots with erythematous base on buccal mucosa opposite molars, pathognomonic |
| Roseola infantum (HHV-6/7) | Nagayama spots | Erythematous papules/ulcers on soft palate and uvula |
| Scarlet fever (Streptococcus pyogenes) | Strawberry tongue | Initially white coating with prominent papillae → progresses to bright red tongue |
| Infectious mononucleosis (EBV) | Petechiae on soft palate | May mimic Forchheimer spots; usually with exudative pharyngitis, lymphadenopathy |
📌 Key Differentiation
- Koplik spots (measles) = pathognomonic
- Forchheimer spots (rubella) = soft palate petechiae
- Nagayama spots (roseola) = soft palate/uvula papules
- Strawberry tongue (scarlet fever) = red tongue with prominent papillae
- Palatal petechiae in mono = EBV, must differentiate from rubella
🔹 Forchheimer Spots
Definition:
- Small, reddish petechiae or macules that appear on the soft palate.
Clinical Associations:
- Classically seen in Rubella (German measles).
- Can also appear in infectious mononucleosis, scarlet fever, and occasionally measles.
Timing:
- Appear early in the course of illness, sometimes before or with rash.
Key Points:
- Not pathognomonic → unlike Koplik spots in measles.
- Help in differential diagnosis of viral exanthems.
- In rubella, they often accompany triad: rash + lymphadenopathy + mild fever.
Differentials (comparison of oral enanthems):
- Koplik spots (measles): bluish-white on buccal mucosa.
- Nagayama spots (roseola): red papules on soft palate/uvula.
- Strawberry tongue (scarlet fever): red papillae on tongue.
🔹 Koplik Spots
Definition:
- Pathognomonic oral lesion of measles (rubeola).
- Appear as bluish-white or grayish papules with a reddish areola.
Location:
- Found on the buccal mucosa, usually opposite the lower 2nd molars.
Timing:
- Appear 1–2 days before the measles rash.
- Disappear as the exanthem spreads.
Key Features:
- Considered a diagnostic sign of measles.
- Sometimes described as “grains of salt on a red background.”
- Differentiate from:
- Forchheimer spots (rubella): petechiae on soft palate.
- Nagayama spots (roseola): papules on soft palate/uvula.
- Strawberry tongue (scarlet fever): erythematous tongue with prominent papillae.
Clinical Use:
- Helps in early diagnosis before full measles rash appears.
- Important for isolation & public health measures.
1. Koplik spots are pathognomonic for which disease?
2. Typical location of Koplik spots is:
3. Appearance of Koplik spots is often described as:
4. Koplik spots appear in relation to measles rash:
5. Koplik spots are best differentiated from which oral lesion of rubella?
6. Koplik spots are most visible during which phase of measles?
7. Which symptom commonly precedes the appearance of Koplik spots?
8. Which best describes the diagnostic value of Koplik spots?
9. Koplik spots usually disappear:
10. In terms of morphology, Koplik spots are:
11. Koplik spots were first described by:
12. The measles rash typically begins:
13. Koplik spots are useful because:
14. Koplik spots can be confused with:
15. Which WHO strategy relies on early recognition of Koplik spots?
16. Koplik spots are most commonly observed in:
17. The measles virus belongs to which family?
18. Complication least likely in measles is:
19. Koplik spots are best examined under:
20. Koplik spots are transient, but their diagnostic value lies in:
