Infantile and juvenile acne are well-recognized entities, presenting as an acne-like rash, usually on the cheeks and chin of infants . The areas involved are well-defined;  the lesions  often  remain noticeably  limited to these sites and usually consist of comedones and papules . Superficial pustules may occasionally arise but nodules  and cysts  are  rare. Although data are  limited,  it would appear that there is often a relationship between infantile acne and a family  history of acne.63 There are no studies indicating a relationship between acne in pregnancy and the occurrence of infantile acne.

Under exceptional circumstances, infantile or juvenile acne may be a manifestation of sexual precocity; the child should therefore be examined and investigated, if necessary,  for such conditions as the androgenital syndrome. A case of infantile acne associated with transient increases  in  concentrations  of luteinizing  hormone, follicle stimulating hormone and  testosterone has been reported. It was postulated that these  abnormalities were due to delay in maturation of the  hypothalamic 'gonadostat'.

  The possibility of contact with an acnegenic agent or ingestion of a halogen, although unlikely, must also be considered. One patient with infantile acne has been reported with the fetal hydantoin syndrome - this is characterized by mental and growth retardation, unusual facies, digital nail hypoplasia and coarse scalp hair. The link with infantile acne may be fortuitous.

  Infantile acne often lasts until the age of 3-4 years but it may regress after eighteen months or persist even until the age of five or six years. There are no detailed investigations of the overall relationship between juvenile acne and the predisposition to acne later in life.

  The most outstanding contribution  to the  clinical understanding of infantile  and juvenile acne has been made by the  Italian dermatologist Bessone.  He reviewed most of the world's  publications on  infantile acne up to 1974.66,67 He has personally studied more than sixty patients over twenty years. In most patients (of whom 80 per cent were male) the onset  was in the first twelve months. Bessone's earlier observations suggested a genetic trait; he clearly demonstrated that a family history of acne was present in 77 per cent of such subjects.67 Although virtually all subjects showed no evidence of other androgenic abnormalities, many had abnormally high excretion  of 17-ketogenic steroids.

  The mechanism of infantile acne is unknown. Males are affected much more than females which may provide  a clue to the understanding of this type  of acne. The  endocrine  environment of the  fetus could be important. Testicular androgen is more  actively produced in  utero  than are adrenal androgens,68 which may  account for the greater incidence of juvenile acne in males.  Studies  of  surface  lipid composition and microbiological flora have not been reported  in infantile acne. However, Agache et al have investigated sebum excretion in infants and showed that sebum excretion is relatively high within a few days of delivery, remains high for twelve weeks and then gradually falls to a very low level by six months. This study did not  include subjects with infantile acne.

  There  is often no doubt about the diagnosis. However,  there is one report of a Candida  infection in an eight-week-old  infant which  masqueraded as  infantile acne; the infant's mother had vaginal  candidiasis.

  Treatment of infantile acne is straightforward. Mild cases  do well with either topical benzoyl peroxide or retinoic acid.  If there are many comedones,  retinoic acid is the drug of choice; if more inflamed  lesions are present, benzoyl peroxide is to be preferred.  If the acne is severe then oral erythromycin suspension  125 mg tds is required  for six months.  Topical  therapy may be required for 3-4 years. Oral tetracycline must never be used because of the inevitability of yellow discolouration  of the permanent teeth.  In one  severe case, oral isotretinoin has been used successfully in  a dose of 1 mg/kg for four months  (Vickers, personal communication 1986).