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Azelaic acid (20%) cream in the treatment of acne vulgaris

2002; Wiley; Volume: 16; Issue: 2 Linguagem: Inglês

10.1046/j.1468-3083.2002.00392_6.x

1468-3083

Avner Shemer, Geoffrey R. Weiss, Boaz Amichai, B Kaplan, Henri Trau,

Nail Diseases and Treatments

Azelaic acid (AZA) is a naturally occurring saturated nine-carbon dicarboxylic acid (COOH-(CH2)7-COOH), possessing a variety of biological actions both in vitro and in vivo.1 AZA has insignificant effects on normal cells. The physiopathological mechanism of acne seems to depend on several factors: (i) a hyperkeratinizing process of follicular channels; (ii) microbial colonization of pilosebaceous units; (iii) perifollicular inflammation; (iv) sebum production and excretion; and (v) differential rates of conversion of testosterone to dihydrotestosterone.1 AZA is an antikeratinizing agent displaying an antiproliferative cytostatic effect on keratinocytes (by inhibiting DNA synthesis) and modulating the early and terminal phases of epidermal differentiation (by inhibiting cytoplasmic protein synthesis).2 Both in vitro and in vivo, AZA cream has an antibacterial effect,3,4 which is primarily initiated by the inhibition of the bacterial protein synthesis.5 The application of 20% AZA cream over a 3–6-month period did not affect excretion rate6,7 or composition of sebum2 or the morphology of sebaceous glands2 in acne patients. Nevertheless, patients with acne using AZA for 1–2 months, reported subjectively gradual and progressive reduction in skin greasiness.3 AZA's effect on testosterone metabolism remains controversial. AZA also has an antipigment effect, probably through its competitive inhibition of oxido-reductive enzymes, such as tyrosinase, and mitochondrial respiratory enzymes.1 Topical 20% AZA cream applied twice daily for 6 months was of comparable efficacy with topical 0.05% tretinoin cream,8 topical 5% benzoyl peroxide gel,7 topical 2% erythromycin cream9 and oral tetracycline 0.5–1.0 g/d in comedonal and mild–moderate (80%) and moderate–severe (60%) inflammatory types of acne.4,10 We conducted an open prospective study, including 46 patients (19 men and 27 women), aged 14–25 years, with recurrence of acne or inadequate acne response to other therapies. The study ran from the month of February until April of the following year. Acne grading was based on the Cunliffe score (Leeds technique), a photonumeric grading scale.6 Inclusion criteria for this study were patients over 14 years of age, with acne grades 1–3 (without cystic acne). All previous acne treatments (comedolytic preparations, local antibiotics and oral minocycline) were discontinued 1–3 months, respectively, prior to this study. Patients applied topical 20% AZA cream (Skinoren®, Schering Berlin, Germany) on affected areas once a day for the first week and twice a day for the next 23 weeks. All patients were told the cream may cause mild stinging and to apply a very thin layer. Follow-up visits were required at the beginning of the study, and then at weeks 3, 9, 15, 24 (end of treatment) and 30 (6 weeks after end of treatment). All patients were examined by the same investigator before the study and throughout the study period. Forty patients (87%) completed the study. Drop-outs were those who failed to attend a follow-up session, not due to side-effects. Before treatment, no patients (0%) had 0–1 grade acne vulgaris, 31 patients (77.5%) had grade 1–2 acne and nine patients (22.5%) had grade 3 acne. At week 30, 34 patients (90%) were in grade 0–1 acne and were satisfied from the decrease in comedone number and in the number of papular and pustular lesions (see Table 1 and fig. 1). At week 30, hyperpigmentation in resolving acne in our 26 patients with Fitzpatrick skin complexion of 3–4 was assessed. Of those 26 patients, at the beginning of the study, 23 (88%) had grade 1–2 acne vulgaris and three (12%) had grade 3 acne. At week 30, 22 patients (85%) had grade 1–2 or 0–1 acne, with mild or no hyperpigmentation where lesions had resolved. In resolved lesions, the skin was the same pigmentation as uninvolved skin. Four patients (15%) remained with hyperpigmentation and acne grade 1–3. No serious adverse effects were noted. There were three cases of mild stinging sensation that resolved spontaneously and did not require stopping the trial. Grade of acne vulgaris in patients by percentage at each visit. Although effects on pigmentation were not assessed at the beginning of treatment and at each follow-up session, AZA may be an ideal choice in treatment in patients with acne, especially those with a tendency for hyperpigmentation, and should be considered in the rare case of a patient with both acne and melasma occurring simultaneously. We recommend a large controlled study with follow-up visits at 3–4-week intervals, to investigate these findings further.