Dermatitis

Seborrhoeic dermatitis

This is an inflammation of the upper layers of the skin, which gradually results in dry or greasy scaling of the affected area. This type dermatitis tends to be chronic and recurrent. It occurs in both infants and adults and tends to run in families. In infants, this condition is known as ‘cradle cap’ when it occurs on the scalp, but can also affect the nappy area to cause ‘nappy eczema’. In adults, the rash tends to occur around the nose, eyebrows and scalp.

Treatment

Infants: wash the scalp with mild shampoo. Oil can be applied to help comb scale out.

Adults: regular use of an anti-dandruff shampoo is often all that is needed.

Corticosteriods can also be applied, only 1% strength to the face. Ketoconazole 1% shampoo and cream are very effective.

Contact dermatitis

Contact dermatitis is inflammation of the skin caused by contact with a specific substance. This happens because of irritation or by an allergic reaction.

Substances that can trigger this inflammation can include cosmetics, soaps, detergents, rubber, nickel (in jewellery) or specific chemicals used in skin creams or from plants.

With an allergic reaction, it is not the first exposure that causes a reaction but may be the next exposure or, in some cases, it is possible to have contact with a substance for a number of years without any skin inflammation occurring. But once the skin has become sensitive, even a tiny amount of that substance can cause a reaction.

Usually contact dermatitis affects only the area that has been in contact with the trigger or irritant (item that has caused the reaction).

Symptoms can vary from a mild rash to a severe rash and blisters, with subsequent scaling and itching. The severity depends on the concentration of the irritant and how long the skin was exposed to it. Once the irritant is taken away, the redness and rash usually disappear over a few days.

Treatment

A dermatologist can perform patch testing to find out which substances are causing the allergic reaction. This is done by placing small discs (with possible allergen-causing substance on them) on the skin and removing them after 48 hours for examination. The patches are then examined again 2 days later, to check for delayed reactions. Once the trigger has been identified, it is important to avoid it as continued exposure may cause a persistent rash, which will be difficult to treat.

Treatment involves the use of steroid creams to decrease the symptoms of the reaction. With severe contact dermatitis, oral steroids or a steroid injection may be given.

This page was last updated at 3:45PM on November 8, 2021.