Subjects  with  mild acne   should be assessed to determine whether the condition is predominantly inflammatory or noninflammatory or a mixture of  these types  of lesions.  Subjects with predominantly noninflammatory acne should be given retinoic acid. This should be applied once or twice daily to all areas and, if appropriate, not just to the face but also to the back and chest.

 

  The patient should  be told that,  if  there  is  any unacceptable erythema or scaling as a result  of  the topical therapy, then the frequency of application can be modified. Certain areas are more prone to irritation than others, such as the neck and below the eyes though at the latter site treatment is rarely needed since acne lesions are uncommon.

 

  If the patient has  many obvious blackheads, they could be  removed by  a nurse, or,  if  the  family  is capable, then they too  could remove the blackheads. Unfortunately, both in hospital and in the community, the style and type of comedone removers  leave much to be desired - in the UK at least.

 

  If the patient has multiple inflammatory lesions and very few noninflamed lesions, benzoyl peroxide preparations are the drugs  of choice.  The physician should start with a 5 per  cent concentration. If the  patient  is fair-haired it is not unreasonable to begin  with a 2.5 per cent concentration, but scientific proof of this clinical dogma is lacking.

 

  Initially, the patient should be  reviewed every 3-4 months and,  if there is a  satisfactory improvement, therapy continued  with  the same  topical preparation. Topical antibiotics and azelaic acid (should  it  be approved) are very reasonable alternatives to benzoyl peroxide.  If the acne is not responding  well but still does not merit oral therapy, the concentration of benzoyl peroxide can be increased to 10 per cent or 20 per cent. It should be stressed that adequate dose-response studies are, with one exception, lacking (Cunliffe WJ, Forster RA, data  presented at the 17th International Congress of Dermatology,  1987) though  the patient may appreciate  an  increase in  concentration, while being unaware that it has little scientific basis.

 

  Some patients have mixed noninflamed and inflamed lesions; such patients can be given retinoic acid in the morning and a benzoyl peroxide preparation,  or a topical antibiotic, in the evening.88 If there is  any irritant dermatitis, they could use the two preparations on alternate days.

 

  Topical treatment is indicated in three situations in those with mild acne: alone, or in conjunction with oral therapy (combined therapy is better  than  single therapy); and as maintenance after  oral therapy has been discontinued.