Eczema describes a group of conditions that cause inflamed, irritated and often itchy skin, as well as individual conditions within that group. Seborrheic dermatitis falls within the broader classification because it can share the characteristic eczema changes in the skin. The word eczema can name a whole group or one member of it, which is a lot of administrative responsibility for one word.13

What is the difference between seborrheic dermatitis and eczema?

When eczema means atopic dermatitis, these are different diagnoses, which makes the vocabulary less helpful than it looks. Atopic dermatitis is a lasting inflammatory condition with itching and recurring flares. Seborrheic dermatitis commonly affects the scalp and face; yeast living on the skin and sebum, the skin's oil, are thought to play a role.1245

FeatureSeborrheic dermatitisAtopic dermatitis
Typical patternScaly, itchy and red patches on the scalp, face or other areas.Dry, scaly skin with itching that can be intense.
Factors involvedSkin yeast and sebum are thought to contribute.Genes, the immune system and substances touching the skin can contribute.
In babiesCan cause cradle cap and moist red areas in skin folds; usually not itchy.Often affects the face and outer surfaces of the limbs; itching is a key feature.
Treatment approachTreatment can reduce the rash, itch and swelling and help prevent flares.Treatment combines skin care, managing triggers and medication.
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Dermatitis means inflammation of the skin, not one specific diagnosis, so the longer name has not done all the explanatory work, despite arriving dressed as an explanation. Similar looking rashes still need to be distinguished: seborrheic dermatitis is one of the conditions considered when checking whether a rash is atopic dermatitis.12

Can eczema affect the face?

Yes. Atopic dermatitis can affect the face, particularly in infants and children, and can develop on the eyelids and around the eyes. Seborrheic dermatitis also commonly affects the face. Location alone therefore cannot tell you which condition you have. A clinician considers the rash's appearance, itching, history and pattern rather than treating every facial patch as the same problem.125

Is cradle cap eczema?

Cradle cap is seborrheic dermatitis in babies, not another name for atopic dermatitis. Infantile seborrheic dermatitis is often mistaken for atopic eczema, but it generally does not itch and can cause moist red patches in skin folds as well as scalp crusts. It tends to improve after six months of age. Atopic dermatitis has itching as an essential feature, so that difference helps a clinician assess a baby's rash.25

What should you do about scalp flakes?

Scalp flakes alone do not identify the cause. Dandruff can be associated with seborrheic dermatitis, eczema and other skin conditions. For ordinary dandruff, an antidandruff shampoo is a reasonable first step; facial patches or an inflamed scalp deserve medical assessment.6

  1. 1For dandruff, choose an antidandruff shampoo containing ketoconazole, coal tar or salicylic acid.
  2. 2Ask a pharmacist how to use the shampoo. The application instructions depend on the product.
  3. 3Use the shampoo for up to four weeks to see whether the dandruff improves. More than one type can be needed to find one that works.
  4. 4See a doctor if symptoms persist after at least four weeks, the dandruff is severe, the scalp is very itchy, red or swollen, or flaky, itchy patches affect the face or body.
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When should the diagnosis be checked?

Arrange an assessment if the rash is painful, behaves unusually or is not responding to treatment. Bring details of the cleansers, moisturizers and medicines you use, where you apply them, and any stinging they cause. Also mention disrupted sleep or repeated skin infections. These details help the clinician assess both the diagnosis and the impact of the rash.26

Where this answer comes from

  1. 1Eczema pathologydermnetnz.org
  2. 2Guidelines for the diagnosis and assessment of eczemadermnetnz.org
  3. 3Eczema Resource Centeraad.org
  4. 4GUIDELINES OF CARE FOR THE MANAGEMENT OF ATOPIC DERMATITIS: Part 1: Diagnosis and Assessment of Atopic Dermatitispmc.ncbi.nlm.nih.gov
  5. 5search.aad.orgsearch.aad.org
  6. 6Dandruffnhs.uk