News forum: In Brief

Silver Dressings in venous ulceration
There is no evidence to support routine use of silver-donating dressings beneath compression for venous ulceration, according to the results of a randomised controlled trial. The UK trial involved 213 patients with venous ulcers, randomised to silver-donating or non-silver, low-adherence dressings. There was no difference in the proportion of ulcers healed at 12 weeks among those treated with silver-donating (59.6 per cent) versus 'control' dressings (56.7 per cent). Median healing time for patients treated with silver dressings was 67 days, compared to 58 days for controls. The cost of silver dressings, including staff time and materials, was more than 30 per cent higher than for non-silver dressings (£417.97 versus £320.12).
Michaels JA, Campbell B, King B et al. Br J Surg 2009; 96(10): 1147-56

Psoriasis and cancer risk
Psoriasis patients appear to have an increased risk of cancer, according to an analysis of data from the General Practice Research Database. Among 67,761 patients, 1,703 had incident cancer, of whom 54 per cent had a history of psoriasis. Incidence rate ratios for lymphohematopoietic and pancreatic cancers were 1.81 and 2.20, respectively. A nested case-control analysis found a 50 per cent increased risk of cancer overall for psoriasis of four or more years' duration and a 53 per cent increased risk for patients receiving systemic treatment. The OR for patients not on systemic therapy was 1.59 for psoriasis of less than two years and 2.12 for disease lasting two years or more. The authors say further research is needed to confirm their findings.
Brauchli YB, Jick SS, Miret M et al. J Invest Dermatol 2009; 129(11): 2604-12

Loose anagen hair syndrome
A trichogram can be instrumental in confirming a diagnosis of loose anagen hair syndrome (LAHS), the authors of a retrospective survey say. The study was carried out to categorise LAHS more clearly and compare it with other forms of childhood alopecia. It involved data from 374 patients with alopecia referred to an academic paediatric dermatology practice. About 10 per cent of children with alopecia had LAHS; the most common age of onset was three years and the most common symptom reported was thin, sparse hair. All but one of 37 patients with LAHS were female. In 32 of 33 patients, trichograms showed typical loose anagen hairs; however, no laboratory test result abnormalities were noted among those who underwent testing.
Cantatore-Francis JL, Orlow SJ. Arch Dermatol 2009; 145(10): 1123-8

Laser therapy and melanoma

High-dose low-level laser therapy (LLLT) should not be used over melanoma because it may increase tumour growth. Researchers in Norway and Brazil carried out in vitro and in vivo experiments in mice and found that while high-dose LLLT did not cause significant changes in the cell cultures, direct irradiation of tumours in mice led to a significant increase in tumour mass volume and considerable histological alterations, indicating a worsening of disease. The researchers stress that this contraindication should be implemented in clinical practice so that LLLT can remain a safe treatment.
Frigo L, Luppi JS, Favero GM et al. BMC Cancer 2009; 9(1): 404

Prevalence of psoriatic arthritis
The prevalence of psoriatic arthritis (PsA) has been estimated at 13.8 per cent in a UK study. People with psoriasis were identified from 22,500 patients at two general practices using computer records. The 633 patients were sent a questionnaire and half of the respondents were clinically assessed. All patients noted as having psoriasis were cross-referenced with a secondary care index for PsA and rheumatoid arthritis. Twelve out of 93 people who underwent examination fulfilled the criteria for PsA; however, six of the examined individuals did not have psoriasis. The researchers say that misclassification of psoriasis and arthritis and response bias mean the 13.8 per cent prevalence for PsA is likely to be an overestimate.
Ibrahim G, Waxman R, Helliwell PS. Arthritis Rheum 2009; 61(10): 1373-8

Lupus-like syndrome
A retrospective review of patients with lupus-like syndrome attributable to TNF-alpha inhibitor therapy has been undertaken by US researchers. The review, conducted from 2000 to 2008, found that a lupus-like syndrome occurred after a mean treatment duration of 16.2 months in 14 patients, 12 of whom were female. Thirteen patients had received infliximab and one, adalimumab. The researchers noted that, compared with previous studies, cutaneous findings were less frequent and arthritis more frequent in their cohort. All patients improved after stopping treatment and four out of five patients tolerated an alternative TNF-alpha inhibitor without recurrence of the syndrome.
Wetter DA, Davis MD. Mayo Clin Proc 2009; 84(11): 979-84

Methotrexate in chronic urticaria
Methotrexate could prove useful in the treatment of steroid-dependent chronic urticaria. Researchers at St John's Institute of Dermatology in London carried out a retrospective case-note review of 16 patients with steroid-dependent chronic urticaria who received methotrexate after a median disease duration of 48.5 months. Twelve of the 16 patients responded. Three showed some benefit, seven showed considerable benefit and two cleared. The dose to achieve a steroid-sparing effect was 10-15mg weekly (cumulative dose range 15-600mg, median 135mg) and the drug was well tolerated. The researchers suggest the beneficial effects of methotrexate may be anti-inflammatory and immunosuppressive.
Perez A, Woods A, Grattan CE. Br J Dermatol 2009; doi: 10.1111/j.1365-2133.2009.09538.

Dirt may be healthy for children
A grubby child may be a healthier child, according to US researchers. They found that staphylococcal bacteria on the skin can temper the inflammatory response to injury. Experiments in mice and human cells showed that staphylococci produce lipoteichoic acid. This acts selectively on keratinocytes to inhibit inflammatory cytokine release from the keratinocytes and the inflammation triggered by injury, thus moderating any overly aggressive response. The researchers say their study provides a molecular basis for understanding the hygiene hypothesis, as well as revealing elements of the wound repair response that were previously unknown.
Lai Y, Di Nardo A, Nakatsuji T et al. Nature Med 2009; doi:10.1038/nm.2062