Acne Treatment Guide
What is Acne? Acne is an extremely complex disease with elements of pathogenesis involving defects in epidermal keratinization, androgen secretion, sebaceous function, bacterial growth, inflammation, and immunity.
In the past 30 years, much has been worked out, and we now have a fairly detailed understanding of the events that result in an acne pimple, although there is also much left to be discovered.
Acne Treatments The effects of hormones in acne are most notable in women.
Androgens such as dihydrotestosterone (DHT) and testosterone, the adrenal precursor dehydroepiandrosterone sulfate (DHEAS), estrogen, and other hormones, including growth hormone or insulin-like growth factors (IGFs), may each be important.
It is likely that the hormones affecting the sebaceous gland are both taken up from the serum in addition to being made locally within the gland.
Hormonal therapy is an option in women whose acne is not responding to conventional treatment or if signs of endocrine abnormalities are present.
The greatest therapeutic benefit from hormonal therapy is achieved in combination with other effective anti-acne medications.
This chapter focuses on the role of hormones in acne, the clinical presentation of adult female acne, the work-up of a suspected endocrine abnormality, and the available options for hormonal therapy.
BENZOYL PEROXIDE Benzoyl peroxide is a topical disinfectant that was originally used as a peeling agent for acne.
Its mechanism of action is through lowering P.
acnes populations by oxidative killing, and the drug is extremely effective as a topical agent.
When applied to the skin, BP breaks down into benzoic acid and hydrogen peroxide.
It assumed that the peroxide accounts for the majority of bactericidal activity, but no studies have been performed to assess the activity of benzoic acid in acne.
The major side effect of BP is irritation, which usually is easily managed with moisturizers.
However, BP has been reported as a contact sensitizer in as many as 4% of patients and can reach nearly 75% when applied to leg ulcers, but in clinical acne practice actual contact allergy is rarely noted.
As a heavy prescriber of the drug, I see, at most, a case every few years.
Various concentrations of BP are available, but there is no convincing data to prove that high concentrations are more effective than lower ones.
P.
acnes reduction is as effective by 2.
5% as 10% BP, and one small study shows therapeutic equivalence between 2.
5%, 5%, and 10% BP gels and a lower rate of irritation with 2.
5% than the higher concentrations.
BP washes are useful in particular for trunk acne since they can cover a large area easily, but in the past have been of fairly low potency.
Newer formulations have been designed to have greater substantivity and are capable of P.
acnes reductions near that of traditional gels and creams.
As a single agent, BP is superior to clindamycin.
Combination products of BP plus erythromycin or clindamycin have been developed and are more effective clinically than either product alone.
MACROLIDES Topical and oral erythromycin and topical clindamycin have been well-established acne treatments for decades, but have become much less effective in the past 15 years or so due to the acquisition of resistance by P.
acnes.
Resistant bacteria are now induced quickly by macrolide therapy because most patients have a portion of 97 their normal skin flora that is genetically resistant, and that subgroup expands under the selective pressure of therapy.
Resistant bacteria make for acne that resists therapy and erythromycin resistant strains are typically resistant to clindamycin and vice versa.
Resistance can be combated by the addition of BP to topical macrolide regimens.
It has been clearly shown that such combination products are not only more effective than monotherapy with macrolides, but also do not permit the survival of resistant populations of P.
acnes.
Other macrolides for example, azithromycin have been reported in small studies to be of value in acne, but no data is available on the effect of resistance on the utility of these drugs.
TETRACYCLINES The tetracycline family of antibiotics are extremely useful in acne because they have multiple modes of action, functioning as antibiotics that reduce bacterial populations, and as anti-inflammatory drugs that attack acne from a second front.
Tetracyclines, especially doxycycline and minocycline are highly antiinflammatory in many cell systems.
Neutrophil and monocyte chemotaxis is inhibited through calcium chelation, blunting the migration of cells to the follicle is inhibited; with minocycline and doxycycline roughly 10-fold more active than tetracycline.
In this model, macrolides and cephalosporines were inactive.
Protein kinase C is inhibited, perhaps interfering with signal transduction.
Generation of reactive oxygen species and the oxidative burst in neutrophils is decreased.
Nitric oxide production is modulated.
Matrix metalloprotease and collagenase activity is inhibited.
In vivo, tetracyclines have been demonstrated to be highly active in treating purely inflammatory diseases including rheumatoid arthritis, bullous pemphigoid, and sarcoidosis.
Nonantibiotic derivatives of doxycycline have been recently developed that are highly anti-inflammatory and even antineoplastic through inhibition of angiogenesis and may be of use in acne and other inflammatory diseases.
In the past 30 years, much has been worked out, and we now have a fairly detailed understanding of the events that result in an acne pimple, although there is also much left to be discovered.
Acne Treatments The effects of hormones in acne are most notable in women.
Androgens such as dihydrotestosterone (DHT) and testosterone, the adrenal precursor dehydroepiandrosterone sulfate (DHEAS), estrogen, and other hormones, including growth hormone or insulin-like growth factors (IGFs), may each be important.
It is likely that the hormones affecting the sebaceous gland are both taken up from the serum in addition to being made locally within the gland.
Hormonal therapy is an option in women whose acne is not responding to conventional treatment or if signs of endocrine abnormalities are present.
The greatest therapeutic benefit from hormonal therapy is achieved in combination with other effective anti-acne medications.
This chapter focuses on the role of hormones in acne, the clinical presentation of adult female acne, the work-up of a suspected endocrine abnormality, and the available options for hormonal therapy.
BENZOYL PEROXIDE Benzoyl peroxide is a topical disinfectant that was originally used as a peeling agent for acne.
Its mechanism of action is through lowering P.
acnes populations by oxidative killing, and the drug is extremely effective as a topical agent.
When applied to the skin, BP breaks down into benzoic acid and hydrogen peroxide.
It assumed that the peroxide accounts for the majority of bactericidal activity, but no studies have been performed to assess the activity of benzoic acid in acne.
The major side effect of BP is irritation, which usually is easily managed with moisturizers.
However, BP has been reported as a contact sensitizer in as many as 4% of patients and can reach nearly 75% when applied to leg ulcers, but in clinical acne practice actual contact allergy is rarely noted.
As a heavy prescriber of the drug, I see, at most, a case every few years.
Various concentrations of BP are available, but there is no convincing data to prove that high concentrations are more effective than lower ones.
P.
acnes reduction is as effective by 2.
5% as 10% BP, and one small study shows therapeutic equivalence between 2.
5%, 5%, and 10% BP gels and a lower rate of irritation with 2.
5% than the higher concentrations.
BP washes are useful in particular for trunk acne since they can cover a large area easily, but in the past have been of fairly low potency.
Newer formulations have been designed to have greater substantivity and are capable of P.
acnes reductions near that of traditional gels and creams.
As a single agent, BP is superior to clindamycin.
Combination products of BP plus erythromycin or clindamycin have been developed and are more effective clinically than either product alone.
MACROLIDES Topical and oral erythromycin and topical clindamycin have been well-established acne treatments for decades, but have become much less effective in the past 15 years or so due to the acquisition of resistance by P.
acnes.
Resistant bacteria are now induced quickly by macrolide therapy because most patients have a portion of 97 their normal skin flora that is genetically resistant, and that subgroup expands under the selective pressure of therapy.
Resistant bacteria make for acne that resists therapy and erythromycin resistant strains are typically resistant to clindamycin and vice versa.
Resistance can be combated by the addition of BP to topical macrolide regimens.
It has been clearly shown that such combination products are not only more effective than monotherapy with macrolides, but also do not permit the survival of resistant populations of P.
acnes.
Other macrolides for example, azithromycin have been reported in small studies to be of value in acne, but no data is available on the effect of resistance on the utility of these drugs.
TETRACYCLINES The tetracycline family of antibiotics are extremely useful in acne because they have multiple modes of action, functioning as antibiotics that reduce bacterial populations, and as anti-inflammatory drugs that attack acne from a second front.
Tetracyclines, especially doxycycline and minocycline are highly antiinflammatory in many cell systems.
Neutrophil and monocyte chemotaxis is inhibited through calcium chelation, blunting the migration of cells to the follicle is inhibited; with minocycline and doxycycline roughly 10-fold more active than tetracycline.
In this model, macrolides and cephalosporines were inactive.
Protein kinase C is inhibited, perhaps interfering with signal transduction.
Generation of reactive oxygen species and the oxidative burst in neutrophils is decreased.
Nitric oxide production is modulated.
Matrix metalloprotease and collagenase activity is inhibited.
In vivo, tetracyclines have been demonstrated to be highly active in treating purely inflammatory diseases including rheumatoid arthritis, bullous pemphigoid, and sarcoidosis.
Nonantibiotic derivatives of doxycycline have been recently developed that are highly anti-inflammatory and even antineoplastic through inhibition of angiogenesis and may be of use in acne and other inflammatory diseases.
