Follicular hyperkeratinization underlies the development of comedones, the characteristic acne lesion. Although many patients believe that acne stems from a failure to clean the face effectively and sufficiently, researchers have noted it is a failure of the skin and the pores to slough off dead skin cells. Hyperkeratinization is related to the presence of P. acnes in the follicles as it unleashes its enzymatic armamentarium and hides behind the biofilm.
Comedones can be open (blackheads), or closed (white-heads). Retinoids that normalize follicularization are the most effective therapy for acne. Preparations include topical ret-inoids such as tretinoin (all-trans retinoic acid) (e.g., Retin-A, Ortho) and oral retinoids (Accutane tablet).
Acne also involves neutrophil pathology and inflammation. The pustules of acne are filled with neutrophils, which damage the follicle and which are associated with erythema. Because acne is characterized by neutrophils—the “foot soldiers” of inflammation—antibiotics that have anti-inflammatory activity may be used. Examples include tetracyclines, macrolides (e.g., Abbott), (Wyeth), doxycycline canadian (e.g., Vibramycin, Pfizer) at full and submicrobial doses, (Pfizer), and (e.g., Akne-Mycin).
Acne is related to hormonal imbalances. Androgen levels in patients with acne are higher than in controls; people with an-drogen insensitivity syndrome do not develop acne. Acne flares during a woman’s menstrual period, and it may also affect men who take anabolic steroids. It responds to the use of medications that work to “even out” hormonal levels, such as oral contraceptives (e.g., norgestimate/ethinyl estradiol [Ortho Tri-Cyclen, Ortho-McNeil]) or substances that block female hormones (e.g., Pfizer).
As a hormonal disease, acne, particularly in women, is related to excess androgen and is strongly associated with poly-cystic ovary syndrome (PCOS). If patients have irregular menstrual periods and acne, an investigation is recommended to determine the cause of the excess androgen. Sex hormone-secreting tumors, congenital adrenal hyperplasia, and other endocrine diseases marked by excess androgen can result in acne. Men who take testosterone or anabolic steroid supplements also tend to develop acne.
A variety of miscellaneous mechanisms are associated with acne. On the cellular level, acne has been found to be related to defects in T-cell receptors. It is a disease of autoimmunity of sorts in which the body seems to respond to itself with inflammation. Some authors have linked an intake of fatty foods to the occurrence of acne, but this association remains controversial. Smoking may be a clinically important contributory factor to the prevalence and severity of acne.
Topical applications of a variety of substances have been linked to the development of acne. Chloracne, which may be considered to be an acneiform eruption rather than a true manifestation of acne, can be associated with topical exposure to halogens or oils. Examples of halogens include bromides (present in cough syrups and asthma medications), chlorides, fluoride, and iodides (in salt or seafood). Women sometimes develop acne on areas of the face that are covered by hair as well as by oils or pomades for the hair. Mechanics tend to have acne because of the use of oils in their work.
Table 1 Classes and Types of Medications That Can Cause Acne
|Antipsychotic Agents||Hormones||Anticonvulsants||Antibiotics||Elemental Agents||Chemotherapy|
|Trazodone canadian (Deseryl tablet) Haloperidol|
Amineptine (Survector) (off-patent)
(Gleevec) Gefitinib (Iressa)
Acne can also result from oral medications (Table 1). Lithium is a potent inducer of neutrophils and can cause and exacerbate acne. Epidermal growth factor blockers are linked to an acneiform eruption, whose severity parallels clinical effect, which histologically is a folliculitis.
Topical and oral preparations that induce or worsen acne include corticosteroids, which can cause steroid acne; this may be characterized by monomorphous dome-shaped papules on the chest. Steroid acne is often encountered in patients with collagen-vascular diseases or with neurological pathology that requires protracted courses of oral corticosteroids (in particular, potent ones such as dexa-methasone).
Acne excoriee (pathological or compulsive picking at the skin) commonly occurs in young women who pick at scattered acne papules, which are converted into scars; this is as much a psychological disease as a physical disease. Treatment involves selective serotonin reuptake inhibitors (SSRIs) to relieve the urge to pick and isotretinoin tablet to erase all traces of acne that are exacerbated by picking.