Page 1004 - Veterinary Immunology, 10th Edition

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FIG. 30.7 A simplified view of the pathogenesis of atopic
dermatitis. Note the central role of Thymic stromal lymphopoietin
(TSLP).

Thymic stromal lymphopoietin (TSLP) is upregulated in inflamed
skin, especially when associated with epidermal barrier

dysfunction. This TSLP is produced by Th2 cells, keratinocytes, and
mast cells in response to antimicrobial peptides such as β-defensins
and cathelicidins. TSLP is a potent stimulator of Th2 cytokines IL-4,
IL-5, and IL-13, and these in turn promote IgE production. Its
concentration is very high in lesional skin of humans. Intrinsic AD

cases express lower levels of IL-4, IL-5, and IL-13.

Pruritus

Chronic severe itching is one of the most important and distressing
features of canine AD. It is caused by mediators released from

resident skin cells (Fig. 30.8). These mediators bind to itch-specific
neuronal receptors (pruriceptors) that are linked to specific areas of
the brain. Itch mediators include histamine, some prostaglandins

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