What are the effects of topical treatments for seborrheic dermatitis of the scalp in adults?

BENEFICIAL

Ketoconazole

Five randomized controlled trials (RCTs) found that ketoconazole 2% shampoo improved scalp symptoms (including scaling, itching, redness, and dandruff) compared with placebo over four weeks.

Selenium Sulfide

One RCT found that selenium sulfide shampoo reduced dandruff compared with placebo.

LIKELY TO BE BENEFICIAL

Topical Steroids (Hydrocortisone, Betamethasone Valerate, Clobetasone Butyrate, Mometasone Furoate, Clobetasol Propionate)

We found no RCTs comparing topical steroids versus placebo. There is consensus that topical steroids are effective in treating seborrheic dermatitis of the scalp in adults.

Bifonazole

One small RCT found that bifonazole shampoo improved scalp symptoms compared with placebo.

Tar Shampoo

One RCT found that tar shampoo was more effective at reducing scalp dandruff and redness than placebo.

UKNOWN EFFECTIVENESS

Terbinafine

We found no RCTs comparing terbinafine versus placebo in adults with seborrheic dermatitis of the scalp.

What are the effects of topical treatments for seborrheic dermatitis of the face and body in adults?

LIKELY TO BE BENEFICIAL

Topical Steroids (Hydrocortisone, Betamethasone Valerate, Clobetasone Butyrate, Mometasone Furoate, Clobetasol Propionate; Short-term Episodic Treatment in Adults)

We found no RCTs comparing topical steroids versus placebo. There is consensus that short courses of topical steroids used episodically are effective in treating seborrheic dermatitis of the face and body in adults.

Bifonazole

One RCT found that bifonazole improved symptoms compared with placebo after four weeks.

UKNOWN EFFECTIVENESS

Emollients

We found no RCTs of sufficient quality comparing emollients versus no treatment in adults with seborrheic dermatitis of the face and body.

Ketoconazole

Two small RCTs found that ketoconazole 2% cream improved symptoms (erythema, scaling, papules, and pruritus) compared with placebo after four weeks, although the significance of the differences between groups was not clear.

Selenium Sulfide

We found no RCTs of sufficient quality comparing selenium sulfide versus placebo in adults with seborrheic dermatitis of the face and body.

Terbinafine

We found no RCTs of sufficient quality comparing terbinafine versus placebo in adults with seborrheic dermatitis of the face and body.

Lithium Succinate

We found no RCTs of sufficient quality comparing lithium succinate versus placebo in adults with seborrheic dermatitis of the face and body.

Definition

Seborrheic dermatitis occurs in areas of the skin with a rich supply of sebaceous glands. It manifests as red, sharply marginated lesions with greasy looking scales. On the face, it mainly affects the medial aspect of the eyebrows, the area between the eyebrows, and the nasolabial folds. It also affects skin on the chest (commonly presternal) and the flexures. On the scalp, it manifests as dry, flaking desquamation (e.g., dandruff) or yellow, greasy scaling with erythema. Dandruff is a lay term commonly used in the context of mild seborrheic dermatitis of the scalp. However, any scalp condition that produces scales could be labelled dandruff. Common differential diagnoses for seborrheic dermatitis of the scalp are psoriasis, eczema, and tinea capitis.

Incidence and Prevalence

Seborrheic dermatitis is estimated to affect around 1 to 3 percent of the general population.¹ However, this is likely an underestimate because people do not tend to seek medical advice for mild dandruff.

Etiology

Malassezia furfur (i.e.,Pityrosporum orbiculare) is considered to be the causative organism of seborrheic dermatitis and is responsible for producing an inflammatory reaction involving T cells and the complement system. Conditions that have been reported to predispose to seborrheic dermatitis include human immunodeficiency virus²; neurologic conditions, such as Parkinson's disease³; neuronal damage such as facial nerve palsy³; spinal injury⁴; ischemic heart disease⁵; and alcoholic pancreatitis.⁶ In this Clinical Evidence chapter, treatment in immunocompetent adults who have no known predisposing conditions is reviewed.

Prognosis

Seborrheic dermatitis is a chronic condition that tends to flare up and remit spontaneously, and is prone to recurrence after treatment.^1,7