[Eczema].

Pathophysiological characteristics of these two types of eczema, both involve antigen specific effector T lymphocytes and down-regulatory CD4+ T cells (Treg). These cells are responsible for the cutaneous inflammatory response through the production of inflammatory cytokines and the destruction of keratinocytes by apoptosis. The main difference between these two types of disease is the nature of the environmental antigen. Indeed, protein allergens are involved in cases of atopic dermatitis whereas non protein chemicals (calles haptens) are responsible for allergic contact dermatitis. The skin lesions of eczema follow the activation of antigen specific T lymphocytes within the skin, leading to the production of inflammatory cytokines and to the destruction of keratinocytes by apoptosis. CD4+ Treg cells are endowed with down-regulatory and tolerogenic functions since they limit the skin inflammation in patients and prevent sensitization and induction of eczema in normal individuals. Eczema should therefore be considered as inflammatory dermatoses caused by the loss of immune tolerance to environmental antigens. Different strategies capable of restoring immune tolerance could avoid eczema outbursts and/or induce prolonged remissions of the disease.

Eczema↗

PubMed2006

Systematic review of the relationship between early introduction of solid foods to infants and the development of allergic disease.

OBJECTIVE: To assess the evidence that early solid feeding (before age 4 months) increases the risk of allergic disease. DATA SOURCES: MEDLINE, the Cochrane Library, and the Drugs and Pharmacology section of EMBASE with key words "infant," "food," and "allergy." STUDY SELECTION: We found 2719 article citations and reviewed references of relevant articles. We critically evaluated the methods and results of articles that met inclusion criteria. We identified 13 studies that met inclusion criteria. There was only 1 controlled trial. DATA EXTRACTION: Allergic disease. DATA SYNTHESIS: Five studies found a positive association between early solid feeding and eczema, with a persistence of the association for 10 years in 1 study. Four studies found no association. One study found an association between early solid feeding and pollen allergy. We found no strong evidence to support the association between early solid feeding and the development of persistent asthma, persistent food allergy, allergic rhinitis, or animal dander allergy. CONCLUSIONS: Systematic review of available evidence suggests that early solid feeding may increase the risk of eczema. However, there are little data supporting an association between early solid feeding and other allergic conditions. Since many studies had problematic methods, additional controlled trials are needed to help guide physicians as they advise parents about the allergic risks of early introduction of solids.

Eczema↗