Seborrhoeic Dermatitis

What is Seborrhoeic Dermatitis?

Seborrheic dermatitis, also known as ‘cradle cap’ in infants, is an inflammatory skin condition. The condition is common, occurring as red scaly patches in areas of skin that contain many sebaceous glands, such as the scalp, face, and skin folds. Generally, infants and adults are affected. In infants, seborrheic dermatitis is usually mild, occurs during the first two months of life, and tends to resolve on its own within a year. In adolescents and adults, the condition varies in severity over time, usually resolves with treatment, and keeps coming back. Dandruff is considered to be a non-inflammatory type of seborrheic dermatitis.

Can I get treatment for Seborrheic Dermatitis online?

The Online Clinic can prescribe treatment for seborrheic dermatitis online following a consultation.

Who gets Seborrhoeic Dermatitis?

Seborrheic dermatitis has been estimated to occur in 1–5% of the adult population. The condition occurs in people of all ethnicities and is more common in men than in women. The incidence of seborrheic dermatitis is highest in infants in the first three months of life, adolescents, and adults aged 40–60 years. Up to 42% of infants with seborrheic dermatitis of the scalp, face, and skin area covered by a nappy may be affected.

The condition most frequently occurs in people who are immunocompromised such as people with HIV/AIDS and organ transplants or have a chronic neurological or psychiatric disorder such as Parkinson’s disease and depression.

What causes Seborrhoeic Dermatitis?

Many factors have been associated with seborrheic dermatitis, which is most likely to be caused by a combination of factors. These include:

1. Growth of Malassezia, a yeast that normally lives on the skin surface. The antifungal medicine used to treat seborrheic dermatitis reduces the amount of this yeast;
2. Sebum that is produced by sebaceous glands in the skin and released onto the skin’s surface. This is because seborrheic dermatitis appears during the stages of life when the skin produces most sebum and on the areas of skin containing most sebaceous glands; and
3. The body’s immune system. This is because people who are immunocompromised are among those most likely to develop seborrheic dermatitis.

Other factors that may be involved in development of seborrheic dermatitis include genes and neurological and psychiatric conditions.

Who is at risk of Seborrhoeic Dermatitis?

Several factors increase the risk of seborrheic dermatitis, including:

• Age, with infants, adolescents and adults 40 – 60 years of age mostly affected.
• Male sex.
• When activity of sebaceous glands increased and the skin is more oily.
• A deficient immune system due to some conditions, e.g., HIV/AIDS, lymphoma and after an organ transplant.
• A deficient immune system due to some medicines, e.g., immunosuppressants, and PUVA (the medicine psoralen plus exposure to ultraviolet light).
• A neurological disorder, e.g., Parkinson’s disease, and after brain/spinal cord injury.
• A psychiatric disorder, e.g., a mood disorder (depression).
• A genetic disorder, e.g., Down syndrome.
• Cold winter weather.

What are the signs and symptoms of Seborrhoeic Dermatitis?

Seborrheic dermatitis presents as patches of inflamed, scaly, flaking skin. The scales of skin are white/yellow in colour, appear oily, and are mildly itchy (particularly the scalp. The patches appear red on light-coloured skin and usually lighter on dark-coloured skin. Severity varies from a mild condition affecting one or two areas of the body (such as dandruff) to severe widespread condition.

Generally, seborrheic dermatitis develops symmetrically on the body. In infants, it most commonly occurs on the scalp, but the face, ears, body folds (neck, arm pits and groin), and lower truck may be affected. Uncommonly, it develops on the entire body. In adults, the scalp, face (e.g., forehead, in between the eyebrows, eyelids, skin folds running from the nose to corners of the mouth, and beard area), ears, upper chest and back, and body folds (e.g., arm pits, under breasts, belly button, genitals and groin).

How is Seborrhoeic Dermatitis diagnosed?

The diagnosis is usually made by examining the skin for typical features of seborrheic dermatitis.

Seborrheic dermatitis can be mistaken for other conditions affecting the skin, including:
Psoriasis; eczema (atopic dermatitis); tinea capitis (a fungal infection affecting the scalp); rosacea; and lupus. In this case or if another condition is suspected (such as HIV or Parkinson’s disease), other investigations such as blood tests, a medication review, and/or a skin sample (a scraping or biopsy) for microscopic examination or culture may be conducted.

Some medicines (such as chlorpromazine, haloperidol, interferon-alpha, lithium, methyldopa, and psoralens) and nutritional deficiencies (such as niacin, pyridoxine, riboflavin, and zinc), may induce a skin condition similar to seborrheic dermatitis.

How is Seborrhoeic Dermatitis treated?

Treatment (including daily dosing and length of treatment) varies with age of the individual, affected skin area, and severity of the condition. However, gentle washing using soap substitutes, and daily moisturising with emollients that soothe and hydrate the skin is essential at all ages. Severe seborrheic dermatitis needs investigation and specialist treatment by a dermatologist.

Treatment may not be required in infants as the condition may resolve on its own with a few months. Where the scalp is affected, a topical emollient should be used to loosen scales and then washed off. For the nappy area, barrier emollients (such as ointments containing zinc) and frequent nappy changing are advised. If necessary, affected skin areas can be treated with a topical imidazole (clotrimazole or miconazole) cream.

For children, adolescents, and adults, scales in hair and beards can removed using mineral/olive oil for mildly scaly areas and coconut oil/salicylic acid for thickly scaled areas and washing off. They should be washed with medicated/antifungal shampoos (e.g., those containing zinc pyrithione, selenium sulphide, salicylic acid, or ketoconazole) and rinsing after 5–10 minutes. For the face and body, ketoconazole or other imidazole creams and antifungal (ketoconazole)-containing body shampoos are generally effective. Mildly potent corticosteroids (hydrocortisone) may be advised for when the condition flares.

Seborrheic dermatitis can be misdiagnosed as another skin condition such as eczema, psoriasis, impetigo, lupus erythematosus, rosacea, pityriasis versicolor, and Candidiasis.

How can a person with Seborrhoeic Dermatitis help themselves?

Skin areas affected by seborrheic dermatitis are easily irritated, so the skin must be treated gently. Depending on the site of the affected skin, the following tips may help to prevent flare-ups of the condition:

• Use a medicated soap and shampoo recommended by a dermatologist.
• Use fragrance-free and alcohol-free skin care products (e.g., cleansers, moisturisers, shaving cream, shampoos, conditioners, makeup, and sunscreen).
• Wash the face twice daily, hair as often as needed.
• Wash beards and moustache with a medicated shampoo, or shave.
• Protect the skin from dry, cold weather.
• Reduce stress by learning how to manage it and, where possible, avoiding stressful situations.
• Wear cotton clothing that is loose-fitting over affected skin patches to avoid skin irritation.
• Avoid the triggers that cause the condition to flare-up (often the triggers dry the skin), such as harsh skin/hair care products, sweating, dry weather conditions, stress, infections, detergents, and chemicals.
• Treating a flare-up as soon as it begins will help to prevent the condition from worsening.

References

American Academy of Dermatology. Seborrheic dermatitis. Last updated June 2022.
Available from: https://www.aad.org/public/diseases/a-z/seborrheic-dermatitis-overview

Borda LJ, Wikramanayake TC. Seborrheic Dermatitis and Dandruff: A Comprehensive Review. J Clin Investig Dermatol. 2015 Dec;3(2):10.13188/2373-1044.1000019. doi: 10.13188/2373-1044.1000019.

British Association of Dermatologists. Seborrheic dermatitis. Last updated January 2023.
Available from: https://www.bad.org.uk/pils/seborrhoeic-dermatitis/

InformedHealth.org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. Seborrheic dermatitis: Overview. [Updated 2020 Jun 18].
Available from: https://www.ncbi.nlm.nih.gov/books/NBK532846/

The National Institute for Health and Care Excellence. Seborrheic dermatitis. Last revised December 2022.
Available from: https://cks.nice.org.uk/topics/seborrhoeic-dermatitis/

Tucker D, Masood S. Seborrheic Dermatitis. [Updated 2023 Feb 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-.
Available from: https://www.ncbi.nlm.nih.gov/books/NBK551707/