Seborrhoeic dermatitis is an inflammation of the skin that most often affects areas of the body that have a lot of sebaceous glands. These include the skin of the scalp; face; chest; and flexure areas such as the armpits, groin, and abdominal folds. The most typical symptoms of seborrhoeic dermatitis are scaling of the skin and reddish patches. Seborrhoeic dermatitis is fairly common: one to three in 100 people have seborrhoeic dermatitis. The disease is more common in men than in women. Anti-inflammatory, antifungal, and antikeratolytic treatments can be used to treat seborrhoeic dermatitis. The treatment does not cure the disease but relieves the symptoms.
We included 36 randomised controlled trials with 2706 participants, examining the effect of anti-inflammatory treatments on seborrhoeic dermatitis. These trials were short-term; most of them lasting four weeks or less.
Topical steroid treatment (such as hydrocortisone and betamethasone), topical calcineurin inhibitor treatment (such as tacrolimus and pimecrolimus), and topical lithium salts all reduced the symptoms of seborrhoeic dermatitis when compared with placebo treatment. Mild (such as hydrocortisone 1%) and strong (such as betamethasone) steroid compounds were comparable in short-term follow up. Short-term total clearance was achieved with antifungal azole treatment (such as ketoconazole and miconazole), as well as with steroids. Strong steroids were better than azole treatment in reducing erythema, scaling, and pruritus, and were comparable in terms of safety. Steroids were also as effective as calcineurin inhibitors, but side-effects occurred more often with calcineurin inhibitors. We found no differences between calcineurin inhibitors and azole treatments in effectiveness or side-effects. Lithium was more effective than azoles but had a similar frequency of side-effects (one study).
The most common side-effects were burning, itching, erythema, and dryness in all treatment groups.
Topical anti-inflammatory agents are useful in treating seborrhoeic dermatitis. Steroids are the most investigated anti-inflammatories. We still do not know the effects and safety of topical anti-inflammatory treatments in long-term or continuous use. This is regrettable as the disease is chronic in nature. Furthermore, there are no data concerning the effects of different treatments on quality of life.