Non-invasive investigations of skin morphology and function are standard tools to study the pathophysiology of several cutaneous disorders, yet they have not been used in population-based epidemiological studies. Here we examined skin surface pH, stratum corneum hydration, trans-epidermal water loss (TEWL) and skin roughness by profilometry in a study population comprising 377 primary school children (8-9 years old) as part of a multicentre survey on risk factors for allergic diseases in school children. Skin surface pH showed significant higher values (p=0.029) in the group with atopic eczema (n=45) compared with the group without atopic eczema; all other parameters did not differ significantly between children with and without atopic eczema. With increasing skin dryness there was a significant increase in pH values (p=0.004). Stratum corneum hydration showed a significant decrease with increasing dryness (p<0.001). Measurement of skin roughness also revealed a significant linear relationship with skin dryness (p=0.02). It is concluded that measurement of skin surface pH, corneometry and profilometry are useful non-invasive techniques to objectively assess skin dryness in epidemiological studies regarding atopic skin disease.

BackgroundAllergic diseases represent an increasing problem in public health in most modern societies as their prevalence has risen markedly during recent decades. Nevertheless, the causes of this increase are not yet fully explained.ObjectiveWe investigated the correlation of Western lifestyle pattern in varying intensity to the prevalence of atopic diseases in 5 small villages on Karkar Island, in northeast Papua New Guinea.MethodsTwo hundred forty-eight native people from 5 villages on tropical Karkar Island have been included in this study. The degree of Western lifestyle was assessed (questionnaire and observation) for each village. The prevalence of atopic diseases was evaluated by personal and family history, physical and dermatological examination, skin prick test (10 allergens), and measurement of total and specific immunoglobulin E levels (20 common allergens).ResultsThe more easily accessible and thus more "modern" and westernized coastal villages showed a significantly higher prevalence of habitants suffering from atopic diseases than a traditional mountain village (6.8% vs 0.0%, P = 0.034, Fisher exact test). A total of 4.4% (11/248) of the examined islanders suffered from an atopic disease. Atopic eczema seems to be absent on Karkar Island.ConclusionsThe results of this study suggest that so-called Western lifestyle may contribute to the development of atopic diseases.

Atopic dermatitis (AD) is a common inflammatory skin disease: the incidence is increasing in many countries and treatment can be difficult. The aim of this retrospective case series was to examine the effect of oral azathioprine on the clinical severity and serum IgE levels in 38 patients with severe atopic dermatitis. The AD was well-controlled in nearly 80% (30/38). The maintenance dose required was in the range 25-200 mg per day. Four patients withdrew because of adverse affects, including one case of pancytopenia, and a further four ceased azathioprine after 4 months because of a lack of clinical improvement. Total serum IgE levels were measured before commencing azathioprine and after two years of treatment in 26 patients. IgE levels decreased in almost all patients and this was statistically significant (P = 0.012).