Skip navigation

Drug Watch: Treatment of Dandruff

There is growing, though largely indirect, evidence of a relationship between the yeast Pityrosporum ovale and moderate to severe dandruff and seborrheic dermatitis. A number of treatments have become available which treat these relatively common conditions by attacking the causative agent. These include lithium salts, which inhibit small colonies of P. ovale , and ketoconazole and other imidazoles which interfere with steroid synthesis in yeasts.

Bandolier sought evidence of effectiveness through a MEDLINE search using the terms DANDRUFF, DERMATITIS-SEBORRHEIC(exploded to all subheadings) and RANDOM*. This revealed four RCTs (three in English) since 1991; references before 1991 were not used.

Lithium succinate ointment

This is a British multicentre double-blind, randomised, placebo-controlled study of an ointment containing 8% lithium succinate (Efalith) compared with base ointment. The study [1] was designed to be cross-over, but is also analysed as a parallel design (158 patients) which is somewhat easier to understand. Patients were instructed to apply the ointment sparingly to affected areas twice daily for four weeks.

Using 100mm visual analogue scales (VAS), patients assessed redness, scaling, greasiness, itching and the overall impression of treatment. All were significantly better with lithium succinate, with redness, scaling and itching being most improved. There was evidence that the effects of treatment extended at least four weeks after stopping.

Imidazole shampoos and creams

A series of good parallel-group, double-blind randomised controlled trials have been conducted.

An Israeli group examined a shampoo containing 1% bifonazole compared with vehicle shampoo in 44 patients with seborrhoea and seborrheic dermatitis [2]. After using the shampoo three times a week for six weeks with two applications of shampoo on each occasion, there were marked and significant improvements in scaling, redness, itching and severity as assessed by a single clinician.

A similar study of 60 patients with a 2% ketoconazole cream (Nizoral) from Germany also showed significant reductions in redness and scaling.

Perhaps the best of the studies was an RCT which compared ketoconazole 2% shampoo with selenium sulphide 2.5% shampoo and placebo in moderate to severe dandruff. This Canadian study [3] involved 246 patients enrolled after a two week period during which they shampooed twice weekly at home with nonmedicated shampoo; enrolment depended upon the assessment of adherent and loose dandruff at six scalp areas.

Treatment was by twice weekly shampooing by a technician, with clinical assessments at days 1, 8, 15 and 29. The presence of yeast cells was sought by oil immersion microscopy.

Both ketoconazole and selenium sulphide reduced loose and adherent dandruff very significantly over four weeks (by 73% for ketoconazole), and both were much better than placebo. Both also reduced scalp irritation significantly compared with placebo. Ketoconazole reduced the number of patients with yeast cells present from about 80% at the start to 20% at the end of treatment - significantly better than placebo, and somewhat better than selenium sulphide (Figure).

All adverse effects during the treatment phase involved patients treated with selenium sulphide, and although both selenium sulphide and ketoconazole shampoos were effective, ketoconazole appeared to be better tolerated.

References:

  1. A double-blind, placebo-controlled, multicenter trial of lithium succinate ointment in the treatment of seborrheic dermatitis. Journal of the American Academy of Dermatology 1992 26: 452-7.
  2. R Segal, M David, A Ingber, R Lurie, M Sandbank. Treatment with bifonazole shampoo for seborrhoea and seborrheic dermatitis: A randomised, double-blind study. Acta Derm Venereol (Stockholm) 1992 72: 454-5.
  3. FW Danby, WS Maddin, LJ Margesson, D Rosenthal. A randomised, double-blind, placebo-controlled trial of ketoconazole 2% shampoo versus selenium sulphide 2.5% shampoo in the treatment of moderate to severe dandruff. Journal of the American Academy of Dermatology 1993 29: 1008-12.




previous or next story in this issue