An inflammatory disorder of the sebaceous glands, acne vulgaris is the most common skin problem in adolescents, although lesions can appear as early as age 8. Although acne is more common and more severe in boys than girls, it usually occurs in girls at an earlier age and tends to last longer, sometimes into adulthood. The prognosis is good with treatment.
Many factors contribute to acne, but theories regarding dietary influences appear to be groundless. Research now centers on follicular occlusion, androgen-stimulated sebum production, and Propionibacterium acnes as possible primary causes.
Certain drugs, including corticosteroids, glucocorticoids, phenobarbital, phenytoin, isoniazid, lithium, and halogens can cause acne.
Other precipitating factors include exposure to industrial compounds, trauma or rubbing from tight clothing, cosmetics, emotional stress, and unfavorable climate.
Gender Influence: Risks of isotretinoin therapy
Because isotretinoin is known to cause birth defects, the manufacturer, with approval of the Food and Drug Administration, recommends the following precautions:
pregnancy testing before dispensing
dispensing only a 30-day supply
repeat pregnancy testing throughout the treatment period
effective contraception during treatment
informed consent of the patient or parents regarding the drug’s adverse effects.
Androgens stimulate sebaceous gland growth and production of sebum, which is secreted into dilated hair follicles that contain bacteria. The bacteria—usually P. acnes and Staphylococcus epidermidis, which are normal skin flora—secrete lipase. This enzyme interacts with sebum to produce free fatty acids, which provoke inflammation. Also, the hair follicles produce more keratin, which joins with the sebum to form a plug in the dilated follicle.