Health Tips

Your head does not only house one of the most important organs (i.e. brain), but it’s also where the scalp is at; and nobody would want an itchy and inflamed scalp. Not only does it affect one’s appearance, it may also affect one’s quality of life. A long-term, oily inflammation and itchiness on the scalp is known as seborrheic dermatitis (eczema). In babies, such a condition is dubbed as the “cradle cap”. 

An example of a cradle cap.

Dandruff v.s. Seborrheic Dermatitis v.s. Seborrheic Psoriasis?

If your scalp itches and flakes, your doctor can tell if it’s just dandruff or a more serious problem such as seborrheic dermatitis or psoriasis. In general, dandruff involves itchy scalp and flakes falling off your scalp and clinging to your hair or landing on your shoulder. 

However, dandruff is less inflamed and irritated than seborrheic dermatitis. In seborrheic dermatitis, similar inflammation can also be seen in places other than the scalp, such as the sides of the nose, eyebrows, groin, or chest hair, where there is a high density of sebaceous glands (hence the word ‘seborrheic’).  

Seborrheic psoriasis, on the other hand, is an autoimmune disorder that can also affect your scalp, and the red, scaly patches it causes can flake off like dandruff does. However, similar to seborrheic dermatitis but different from dandruff, seborrheic psoriasis is a long-term condition. It usually appears more scaly than flaky, can have serious outbreaks that are red and painful, can spread past hairline to the forehead, back of the neck, or the skin around the ears. Other parts of the body such as elbows, legs and palms may also be affected. An overlapping condition that involves both seborrheic dermatitis and seborrheic psoriasis is known as sebopsoriasis.

Sebopsoriasis of scalp. Image credit : DermNetNZ via Creative Commons Attribution-NonCommercial-NoDerivs 3.0 (New Zealand)

Sebopsoriasis of forehead. Image credit : DermNetNZ via Creative Commons Attribution-NonCommercial-NoDerivs 3.0 (New Zealand)

What causes seborrheic dermatitis?

An inflammatory reaction to excess Malassezia yeast, an organism that normally lives on the skin’s surface, is the likely cause of seborrheic dermatitis. It all happens when the Malessezia overgrow and the immune system seems to overreact to it, leading to an inflammatory response that results in skin changes.

Certain medical conditions can increase people’s risk of developing seborrheic dermatitis, including psoriasis, HIV, acne, rosacea, Parkinson’s disease, epilepsy, alcoholism, depression, eating disorders and recovery from a stroke or heart attack. 

It turns out that seborrheic dermatitis is an unique skin condition that we still barely understand. It can be triggered by the following factors:

• stress

• hormonal changes or illness

• harsh detergents, solvents, chemicals and soaps

• cold, dry weather

• some medications, including psoralen, interferon and lithium

Treatment of seborrheic dermatitis

There are many treatment options for seborrheic dermatitis, such as:

• Ketoconazole + Zinc pyrithione (Dezor Plus®) —  Ketoconazole is effective for reducing flaking and Malassezia counts. Zinc pyrithione helps to remove the dead cells and kills fungi. 

• Coal tar solution + salicylic acid + sulfur (Cera-Scalp®, Sebitar®) — Coal tar has been shown to be effective against seborrheic dermatitis. 

• Selenium sulfide 2.5% shampoo — Sulphur helps to remove the dead cells on the scalp and promotes 

• Betamethasone + salicylic acid (Betacyclic®) — Betamethasone is a type of steroid that can reduce inflammation. 

A word from Doc2Us

If you have any questions related to seborrheic dermatitis, you can consult our professional doctors and healthcare professionals on Doc2Us. Doc2Us is a mobile application that allows you to talk to a doctor or any healthcare professionals via text chat at any time and from anywhere. For better communication, you can even send our online doctor images or voice messages related to your medical inquiry.

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References

1. UpToDate - Seborrheic dermatitis in adolescents and adults

2. Gupta, A. and Bluhm, R., 2004. Seborrheic dermatitis. Journal of the European Academy of Dermatology and Venereology, 18(1), pp.13-26.

Written by

Ms Joyce Toh