ABSTRACT
One of the most common problems seen by dermatologists is acne in its many forms-teenage acne, adult acne, perioral dermatitis, rosacea, etc. The pathogenesis of acne involves the pilosebaceous apparatus-the hair follicle and sebaceous gland are referred to as the pilosebaceous unit or pilosebaceous apparatus. The development of acne begins when the functions within this unit are disrupted. If the follicle becomes irritated for some reason, keratinized cells are overproduced. This may be in response to trauma, material in the unit, hormonal factors, or vascular factors. Once this overproduction of keratinized cells occurs, the stratum corneum in the upper portion of the follicular canal thickens and becomes cohesive. There is no longer normal shedding but an accumulation of corneocytes (retention keratosis) with formation of
the microcomedone. This precursor of all acne lesions produces obstruction of the canal. Sebum continues to be produced, and retention keratosis continues to progress.
