The Eczema Spectrum
“Eczema” is a clinical term for a group of conditions that cause inflamed, itchy, and erythematous skin. While often used synonymously with Atopic Dermatitis, it is a broader category.
Common Dermatitis Types
| Condition | Key Distinguishing Feature |
|---|---|
| Atopic Dermatitis | Associated with the “Atopic Triad”; filaggrin mutation. |
| Allergic Contact | Type IV (delayed) hypersensitivity (e.g., Nickel, Poison Ivy). |
| Irritant Contact | Non-immunologic; caused by damage from detergents/solvents. |
| Seborrheic Dermatitis | Greasy, yellow scales on sebum-rich areas (scalp, nasolabial folds). |
Diagnostic Approach
- Clinical Assessment: History (triggers, duration, location) and physical exam are primary.
- Patch Testing: Gold standard for confirming Allergic Contact Dermatitis.
- Rule Out: Always consider infectious differentials (e.g., Tinea, Impetigo) if the distribution is atypical or refractory to treatment.
High-Yield Exam Pearl:
- Seborrheic Dermatitis: Associated with Malassezia yeast. First-line treatment involves anti-fungal shampoos (Ketoconazole/Selenium sulfide) and low-potency topical steroids.
- Contact Dermatitis: Distinguish from Atopic Dermatitis by identifying localized exposures that match the lesion distribution (e.g., belt buckle for nickel allergy).