Acne (Pimples) is a common problem seen after puberty, leading to distress, discomfort and disfigurement. It is caused by many factors: Sebacious glands (oil glands of the skin) activity under the influence of androgen hormones Defective keratinisation (cell shedding) leading to partial or complete blockage of the glands Propionibacteria (normal commensals of the skin) acting on the fats of the glands, releasing chemicals that cause inflammation (redness) Eight out of ten adolescents suffer from acne. Those with a family history tend to suffer from severe acne that last longer. Patients with recalcitrant and severe acne and those who develop acne at middle age should be evaluated for underlying endocrinal disorders. Acne can be precipitated by drugs like Lithium, hydantoin, topical and systemic steroids, OCPs, androgens etc.
Clinically acne occur over the face, back and the chest and is characterised by comedones (black heads and white heads), red, raised lesions (Papules and Nodules), pus filled lesions (Pustules) and sometimes cysts. Certain factors can increase the severity of acne like emotional stress, oily cosmetics, tight clothing, working in humid environment etc. Recent studies suggest that high carbohydrate diet [See List of High Glycemic Index Foods] may promote acne through changes in the hormonal milieu, particularly increased levels of insulin which in turn causes an increase in androgen levels. In addition, a diet rich in Omega 6 fatty acids (refined vegetable oils) and poor in Omega 3 fatty acids (fish oils) leads to pro-inflammatory cytokine profile which in turn can increase the development of acne. Omega 3 fatty acids also prevent hyperkeratinisation that leads to comedogenesis. [See Flow Chart below]		Acne may be worsened by high glycemic diet...

Preventive measures include cleansing with soaps or cleansers that are mild and gentle. Too frequent washing so as to render the face non-greasy may also precipitate acne. Use of abrasive cleansers can precipitate comedones. Picking of the comedones can lead to pigmentation. Cosmetic agents should be used carefully. Diet rich in vitamin A and omega 3 fatty acids (fish and fish oils) is useful in prevention of acne.

Treatment of acne: Acne should be treated properly and on time so as to avoid the sequelae such as scarring and pigmentation. Treatment should be done in consultation with a dermatologist who may use the following depending on the type, extent and severity of acne:

Topical Agents:

• Erythromycin (1-4%)
• Clindamycin (1%)
• Benzyl peroxide (2.5, 5, 10%)
• Tretinoin (0.025, 0.05, 0.1%)
• Adapeline (0.1%)
• Azelaic acid (10-20%)
• Keratolytic agents like salicylic acid, glycolic acid (BHA and AHA)
• Anti-inflammatory agents

Systemic Antibiotics (for SIX months):

• Tetracycline: 1000mg/day
• Minocycline: 100mg/day
• Doxycycline: 100mg/day
• Erythromycin: 1000mg/day
• Azithrmycin: 1000mg/day

Isotretinoin (Synthetic Vitamin A) influences all the major pathogenetic factors:

• Reduces sebum production
• Reduces the population of P. acnes
• Reduces ductal cornification
• Anti inflammatory action 

Dose: 0.5-1mg/kg body weight

Adverse effects: Cheilitis, Conjunctivitis, Head ache

Hormones may be useful in cases of hormonal abnormalities

• Oral contraceptive pills containing estrogen and cyproterone acetate
• Glucocorticoids (only in case of congenital adrenal hyperplasia)
• Anti-androgens (for those with features of hyperandrogenism)
  • Cyproterone acetate
  • Spironolactone
  • Ketoconazole
  • Flutamide
  • Cimetidine

Surgical procedures:

• Comedone extraction - helps in faster resolution of acne
• Cryo therapy (CO₂ snow or liquid nitrogen spray) - improves cornification and prevents comedones (See Cryo Therapy)
• Chemical peeling - helps in improving the cornification and also remodelling of the scars. (See Peels)

The table below lists the Glycemic indices and Glycemic loads of various foods and demonstrates that refined grain and sugar products nearly always maintain much higher glycemic index than unprocessed foods and vegetables.

Source: Cordain L. Implications for the role of diet in acne. Semin Cutan Med Surg 24:84-91. Available at
http://thepaleodiet.com/download/18/