Therapy of infected dermatitis: comparative response to two corticosteroid antimicrobial creams

Interventions to reduce Staphylococcus aureus in the management of eczema

BACKGROUND

Staphylococcus aureus (S. aureus) can cause secondary infection in eczema, and may promote inflammation in eczema that does not look infected. There is no standard intervention to reduce S. aureus burden in eczema. It is unclear whether antimicrobial treatments help eczema or promote bacterial resistance. This is an update of a 2008 Cochrane Review.

OBJECTIVES

To assess the effects of interventions to reduce S. aureus for treating eczema.

SEARCH METHODS

We updated our searches of the following databases to October 2018: Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase and LILACS. We searched five trials registers and three sets of conference proceedings. We checked references of trials and reviews for further relevant studies. We contacted pharmaceutical companies regarding ongoing and unpublished trials.

SELECTION CRITERIA

Randomised controlled trials of products intended to reduce S. aureus on the skin in people diagnosed with atopic eczema by a medical practitioner. Eligible comparators were a similar treatment regimen without the anti-staphylococcal agent.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our key outcomes were participant- or assessor-rated global improvement in symptoms/signs, quality of life (QOL), severe adverse events requiring withdrawal, minor adverse events, and emergence of antibiotic-resistant micro-organisms.

MAIN RESULTS

We included 41 studies (1753 analysed participants) covering 10 treatment categories. Studies were conducted mainly in secondary care in Western Europe; North America; the Far East; and elsewhere. Twelve studies recruited children; four, adults; 19, both; and six, unclear. Fifty-nine per cent of the studies reported the mean age of participants (range: 1.1 to 34.6 years). Eczema severity ranged from mild to severe. Many studies did not report our primary outcomes. Treatment durations ranged from 10 minutes to 3 months; total study durations ranged from 15 weeks to 27 months. We considered 33 studies at high risk of bias in at least one domain. We present results for three key comparisons. All time point measurements were taken from baseline. We classed outcomes as short-term when treatment duration was less than four weeks, and long-term when treatment was given for more than four weeks. Fourteen studies evaluated topical steroid/antibiotic combinations compared to topical steroids alone (infective status: infected (two studies), not infected (four studies), unspecified (eight studies)). Topical steroid/antibiotic combinations may lead to slightly greater global improvement in good or excellent signs/symptoms than topical steroid alone at 6 to 28 days follow-up (risk ratio (RR) 1.10, 95% confidence interval (CI) 1.00 to 1.21; 224 participants; 3 studies, low-quality evidence). There is probably little or no difference between groups for QOL in children, at 14 days follow-up (mean difference (MD) -0.18, 95% CI -0.40 to 0.04; 42 participants; 1 study, moderate-quality evidence). The subsequent results for this comparison were based on very low-quality evidence, meaning we are uncertain of their validity: severe adverse events were rare (follow-up: between 6 to 28 days): both groups reported flare of dermatitis, worsening of the condition, and folliculitis (325 participants; 4 studies). There were fewer minor adverse events (e.g. flare, stinging, itch, folliculitis) in the combination group at 14 days follow-up (218 participants; 2 studies). One study reported antibiotic resistance in children at three months follow-up, with similar results between the groups (65 participants; 1 study). Four studies evaluated oral antibiotics compared to placebo (infective status: infected eczema (two studies), uninfected (one study), one study's participants had colonisation but no clinical infection). Oral antibiotics may make no difference in terms of good or excellent global improvement in infants and children at 14 to 28 days follow-up compared to placebo (RR 0.80; 95% CI 0.18 to 3.50; 75 participants; 2 studies, low-quality evidence). There is probably little or no difference between groups for QOL (in infants and children) at 14 days follow-up (MD 0.11, 95% CI -0.10 to 0.32, 45 participants, 1 study, moderate-quality evidence). The subsequent results for this comparison were based on very low-quality evidence, meaning we are uncertain of their validity: adverse events requiring treatment withdrawal between 14 to 28 days follow-up were very rare, but included eczema worsening (both groups), loose stools (antibiotic group), and Henoch-Schönlein purpura (placebo group) (4 studies, 199 participants). Minor adverse events, including nausea, vomiting, diarrhoea, and stomach and joint pains, at 28 days follow-up were also rare and generally low in both groups (1 study, 68 infants and children). Antibiotic resistance at 14 days was reported as similar in both groups (2 studies, 98 infants and children). Of five studies evaluating bleach baths compared to placebo (water) or bath emollient (infective status: uninfected (two studies), unspecified (three studies)), one reported global improvement and showed that bleach baths may make no difference when compared with placebo at one month follow-up (RR 0.78, 95% CI 0.37 to 1.63; 36 participants; low-quality evidence). One study showed there is probably little or no difference in QOL at 28 days follow-up when comparing bleach baths to placebo (MD 0.90, 95% CI -1.32 to 3.12) (80 infants and children; moderate-quality evidence). We are uncertain if the groups differ in the likelihood of treatment withdrawals due to adverse events at two months follow-up (only one dropout reported due to worsening itch (placebo group)) as the quality of evidence was very low (1 study, 42 participants). One study reported that five participants in each group experienced burning/stinging or dry skin at two months follow-up, so there may be no difference in minor adverse events between groups (RR 1.00, 95% CI 0.35 to 2.87, 36 participants, low-quality evidence). Very low-quality evidence means we are also uncertain if antibiotic resistance at four weeks follow-up is different between groups (1 study, 80 participants ≤ 18 years).

AUTHORS' CONCLUSIONS

We found insufficient evidence on the effects of anti-staphylococcal treatments for treating people with infected or uninfected eczema. Low-quality evidence, due to risk of bias, imprecise effect estimates and heterogeneity, made pooling of results difficult. Topical steroid/antibiotic combinations may be associated with possible small improvements in good or excellent signs/symptoms compared with topical steroid alone. High-quality trials evaluating efficacy, QOL, and antibiotic resistance are required.

Interventions to reduce Staphylococcus aureus in the management of atopic eczema

BACKGROUND

Staphylococcus aureus can cause secondary infection in atopic eczema, and it may promote inflammation in eczema that does not look infected. Many antimicrobial products exist for eczema, but it is unclear if they work or if they promote bacterial resistance.

OBJECTIVES

To assess the effects of interventions to reduce Staphylococcus aureus for treating infected or uninfected atopic eczema.

SEARCH STRATEGY

We searched the Cochrane Skin Group Specialised Register (March 2008), the Cochrane Central Register of Controlled Trials (Cochrane Library Issue 1, 2008), MEDLINE (OVID) (from 2002 to March 2008), EMBASE (OVID) (from 2002 to March 2008), Ongoing trials registers (March 2008). References from trials and reviews were searched, pharmaceutical companies were contacted for unpublished trials. There were no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of people with atopic eczema who have been treated with a product intended to reduce S. aureus on the skin.

DATA COLLECTION AND ANALYSIS

Two people independently performed the study selection, data abstraction and quality assessment.

MAIN RESULTS

We included 21 studies (1018 participants) covering 7 treatment categories. Most studies were poorly reported and study differences limited pooling of results. Adverse effects were especially poorly reported, and only one study reported the emergence of resistant bacterial strains following oral antibiotics. Oral antibiotics were not associated with benefit in non-infected (2 trials, 66 participants) or infected eczema (1 trial, 33 participants). We did not find any benefit for antibacterial soaps (1 trial, 50 participants), or antibacterial bath additives (2 trials, 41 participants), or topical antibiotics/antiseptics (4 studies, 95 participants). Adding antibiotics to topical corticosteroids reduced numbers of Staphylococcus aureus in 4 trials (302 participants), but there was no evidence of any clinical benefit in 9 trials involving 677 participants: betamethasone plus neomycin vs clobetasol (MD 1.2; 95% CI 0.25, 2.15), prednicarbate plus antimicrobial vs prednicarbate (RR 0.64; 95% CI 0.25, 1.68), or betamethasone valerate plus gentamicin vs betamethasone (RR 0.31; 95% CI 0.07, 1.35). One trial (30 participants) showed no significant improvement in eczema for those using silver textiles (RR 2.67; 95% CI 0.98, 7.22), despite using 10 times the amount of topical steroids.

AUTHORS' CONCLUSIONS

We failed to find clear evidence of benefit for antimicrobial interventions for people with atopic eczema, despite their widespread use. This does not necessarily mean they do not work because the studies were small and poorly reported. Further large studies with long-term outcomes and clearly defined participants are urgently required.

Treatment of childhood eczema

Eczema in childhood is almost always atopic eczema, a common disease with huge impact on the quality of life of the child and family. Although atopic eczema constitutes part of the atopic syndrome, avoidance of allergens is never enough for disease control. Treatment of eczema in childhood has the same components as in adults. Emollients constitute the preventive background therapy in all stages of eczema, and topical corticosteroids are still the mainstay of treatment. Infectious exacerbation may require the use of a short course of topical or systemic antimicrobials. UV phototherapy should be considered as an adjunctive treatment to assist topical corticosteroids after an acute exacerbation of the disease. Cyclosporine can also be used in the treatment of childhood eczema in severe cases. Maternal allergen avoidance for disease prevention, oral antihistamines, Chinese herbs, dietary restriction in established atopic eczema, homeopathy, house-dust mite reduction, massage therapy, hypnotherapy, evening primrose oil, emollients, and topical coal tar are other temporarily used treatment modalities, without, however, firm evidence of efficacy from proper controlled trials. Calcineurin inhibitors constitute a new generation of drugs for both adult and childhood eczema already marketed in some countries. It is postulated that they will replace topical corticosteroids as first-line treatment of eczema.

Staphylococcus aureus infection on experimental croton oil-inflamed skin in mice

Staphylococcus aureus cells were inoculated on the surface of skin inflamed by application of croton oil in cyclophosphamide-treated mice. Skin specimens were taken at 1, 3, 6, 12, and 24 h inoculation and each specimen was examined by microscopy. The S. aureus cells which attached to the surface of the skin immediately after inoculation had invaded the horny layer within 1 h. The cells gradually penetrated deeper into the epidermis. Electron microscopy revealed fibril-like structures around the S. aureus cells and the cells which adhered to the horny layer and fibrin by means of Ruthenium red-positive, fibril-like structures. A combined application of 0.1% gentamicin ointment, 2% fusidic acid ointment, and clobetasol propionate ointment was more effective in decreasing the number of S. aureus cells in the lesions than was an application of clobetasol propionate ointment alone. However, a combined application of 0.1% gentamicin ointment and 2% fusidic acid ointment without clobetasol propionate ointment showed almost the same efficacy as that with clobetasol propionate ointment. Although povidone iodine killed S. aureus in vitro at a concentration of 0.01% (100 micrograms/ml) in 40 s, its in vivo efficacy was limited.

Comparative merits of two topical corticosteroid antimicrobial drugs

The anti-inflammatory and antimicrobial activities of two topical creams, one containing halcinonide, neomycin and nystatin (HNN), and the other betamethasone valerate, gentamicin, iodochlorhydroxyquin and tolnaftate (BGI), were compared in a randomized, parallel study of 154 patients (eighty-seven secondarily infected eczematous dermatoses; sixty-seven cutaneous candidiasis). Repeated clinical assessments showed that the two creams produced equivalent therapeutic responses both in patients with infected eczematous lesions and candidiasis. HNN and BGI creams eradicated the bacterial pathogens isolated prior to treatment in 80% and 76%, respectively, of the patients with eczematous dermatoses. The organism most frequently isolated in these patients was S. aureus. Local irritation prompting discontinuance of therapy occurred in just one patient receiving HNN, and two patients receiving BGI.