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Case History - Section 1

An adverse reaction to food is best referred to as food hypersensitivity. However, when immunological mechanisms have been demonstrated the appropriate term is food allergy.

When the role of IgE has been demonstrated, the term is IgE-mediated food allergy.

This case history focuses on IgE-mediated food allergy from infancy to 16 years of age.

James is now 16 years old.

He first presented at 8 months with severe atopic eczema (atopic dermatitis).

James was born full term and was breast fed exclusively for 6 months.

Atopic eczema commenced at 6 weeks and became generalized and severe. He was a colicky, unsettled baby.

Solids were introduced at 6 months beginning with rice cereal with some cow's milk formula. His atopic eczema worsened significantly at this stage.



Answer: IgE dysregulation

THIS IS INCORRECT - You are on the right lines since IgE antibodies and a positive Atopy Patch Test (APT) have been found in the majority of adult patients with the IgE-associated sub-group of atopic eczema.

The inflammatory infiltrate in atopic eczema lesions mainly consists of CD4+ T lymphocytes, and a correlation with disease activity can be shown by the proportion of activated and unactivated CD4+ cells, as well as a decrease in the proportion of CD8+ cells.

More than in other allergic diseases, the IgE-associated sub-group, and perhaps also the early stages of atopic eczema in general, is characterized by increased serum IgE levels. This is due to an imbalance of T helper (TH) cell subsets 1 and 2, with a predominance of the IL-4 secreting TH2 cells, with IL-4 as a potent stimulator of the IgE-synthesis. In addition, IL-4 inhibits the production of IFN-gamma at the level of transcription. While TH2 reactions are crucial for triggering reactions in individuals lacking the atopic constitution, in chronic skin lesions TH1 reaction patterns can be observed.

For further information on the causes of atopic eczema in children, access the references below:

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