Implications for Treatment
- Early and aggressive control of acne-associated inflammation
is imperative. This can be accomplished with the use
of a well-rounded treatment regimen that targets multiple
factors in the pathogenesis of the disease and includes
agents with anti-inflammatory properties. Acne treatments with anti-inflammatory effects include topical retinoids, the
oral tetracycline antibiotics, topical dapsone, and azelaic
acid. Among the retinoids, the anti-inflammatory activity of
adapalene has been the most studied. Adapalene has been
shown in vitro and in vivo to decrease expression of toll-like
receptor (TLR)-2 (a receptor of the innate immune system)
and IL-10 (an anti-inflammatory cytokine). (Zuliani T et al.
Exp Dermatol. 2011;20:850-853.) In addition, adapalene increases
expression of CD1d – a cell surface glycoprotein
that plays a role in antigen presentation and induction of
cutaneous inflammatory responses. Other anti-inflammatory
effects of adapalene include inhibition of arachadonic
acid metabolism, neutrophil chemotaxis, and free radical
production.19 Benzoyl peroxide (BPO), through its microbicidal
effects, indirectly reduces inflammation by killing P.
acnes – a trigger of acne-associated inflammation.
A well rounded regimen includes a multi-pronged approach to address the multiple pathogenic factors associated with acne, including follicular hyperkeratinization, P. acnes inflammation, and increased sebum production. Therefore, combination topical regimens that include a topical retinoid, a BPO, and/or an immunomodulating agent (eg, dapsone, azelaic acid) tend to be the most effective.
Under-treatment of acne in patients with skin of color should be avoided, given the greater risk of dyspigmentation and keloidal scarring (in more severe cases). As such, the threshold for using oral antibiotics (for their anti-inflammatory and anti-P. acnes effects) in the appropriate patient is low. Regimens that initially include oral doxycycline or minocycline in combination with a topical retinoid followed by maintenance with a topical retinoid is a well-established long-term treatment strategy in the general acne population,20,21 and is particularly well suited to patients with skin of color.
Oral isotretinoin should also be considered for the appropriate patient with severe inflammatory acne who is at risk for scarring, as well as for patients who fail oral antibiotics. It has been reported based on U.S. National Ambulatory Medical Care Survey data that isotretinoin is less frequently prescribed to blacks than to whites; cost may contribute to this disparity, but patient and provider biases as well as racial differences in severity cannot be ruled out.22 When warranted, oral isotretinoin should be considered early in the course of nodulocystic or other severe forms of acne in patients with skin of color.
In cases of severely inflamed papules or nodulocystic lesions, the use of intralesional corticosteroid injections (typically triamcinolone acetonide 2.5 mg/mL to 3.3. mg/ mL) to rapidly reduce local inflammation is an effective