From the Guidelines
Seborrheic dermatitis is typically diagnosed through clinical examination by a healthcare provider, identifying characteristic symptoms such as red, scaly, greasy patches on the skin, particularly in areas with many oil glands like the scalp, face, sides of the nose, eyebrows, ears, eyelids, and chest. The diagnosis of seborrheic dermatitis involves a thorough assessment of the patient's symptoms, medical history, and physical examination.
- Characteristic symptoms include greasy yellowish scaling, itching, and secondary inflammation from Malassezia yeast, as noted in the clinical practice guideline for acute otitis externa 1.
- The healthcare provider will assess the pattern of skin involvement, the appearance of the scales, and the distribution in sebum-rich areas.
- A skin scraping may be examined under a microscope to rule out other conditions like fungal infections, and a small skin biopsy might be performed in atypical cases to exclude other skin disorders that may mimic seborrheic dermatitis, such as psoriasis or eczema.
- The chronic, relapsing nature of the condition also helps in establishing the diagnosis, as seborrheic dermatitis tends to flare up periodically rather than resolve completely.
- It is essential to consider the patient's medical history, including any triggers like stress or weather changes, and any family history of similar conditions, as seborrheic dermatitis is more pronounced in patients with Down syndrome, HIV infection, and Parkinson's disease, as mentioned in the study 1.
From the FDA Drug Label
Seborrheic dermatitis: Ketoconazole Cream 2% should be applied to the affected area twice daily for four weeks or until clinical clearing. If a patient shows no clinical improvement after the treatment period, the diagnosis should be redetermined. The diagnosis of seborrheic dermatitis is not directly supported by the drug label, it only provides treatment guidance.
- The label suggests that if a patient shows no clinical improvement after the treatment period, the diagnosis should be redetermined 2.
From the Research
Seborrheic Dermatitis Diagnosis
- Seborrheic dermatitis is a chronic, recurring inflammatory skin disorder that manifests as erythematous macules or plaques with varying levels of scaling associated with pruritus 3.
- The condition typically occurs as an inflammatory response to Malassezia species and tends to occur on seborrheic areas, such as the scalp, face, chest, back, axilla, and groin areas 3, 4.
- The diagnosis of seborrheic dermatitis is usually clinical, and specific laboratory and/or instrumental investigations are seldom required 4.
- Seborrheic dermatitis is a clinical diagnosis based on the location and appearance of the lesions, and the skin changes are thought to result from an inflammatory response to a common skin organism, Malassezia yeast 5.
Clinical Presentation
- In adolescents and adults, seborrheic dermatitis clinical presentation may range from mild patches to diffuse scalp scaling 4.
- In infants, it mainly occurs on the scalp as yellowish, scaly patches ("cradle cap") 4.
- Seborrheic dermatitis also may cause mild to marked erythema of the nasolabial fold, often with scaling 6.
- The scales are greasy, not dry, as commonly thought 6.
Diagnostic Considerations
- Stress can cause flare-ups of seborrheic dermatitis 6.
- An uncommon generalized form in infants may be linked to immunodeficiencies 6.
- Several environmental triggers are likely to promote seborrheic dermatitis development, along with fungal colonization by Malassezia spp., sebaceous gland activity, as well as immunosuppression, endocrine, neurogenic and iatrogenic factors 4.