Small intestinal permeability in dermatological disease

Area of Science:

• Gastroenterology
• Dermatology
• Immunology

Background:

• Altered small intestinal permeability is hypothesized to contribute to inflammatory skin conditions.
• The role of gut integrity in atopic eczema, psoriasis, and dermatitis herpetiformis remains unclear.

Purpose of the Study:

• To investigate passive small intestinal permeability in patients with atopic eczema, psoriasis, and dermatitis herpetiformis.
• To determine if abnormal intestinal permeability is linked to the pathogenesis of these skin diseases.

Main Methods:

• Utilized the cellobiose/mannitol differential sugar absorption test in 62 patients with atopic eczema, 29 with psoriasis, and 18 with dermatitis herpetiformis.
• Assessed urinary recovery of cellobiose and mannitol, and the recovery ratio.
• Performed jejunal biopsies in a subset of patients with abnormal permeability.

Main Results:

• The cellobiose/mannitol recovery ratio was normal in most patients with atopic eczema and psoriasis, irrespective of disease severity.
• Abnormal permeability was observed in a minority of eczema and psoriasis patients; one eczema patient had coeliac disease.
• Abnormal permeability was noted in 11 dermatitis herpetiformis patients, with normal jejunal biopsies in seven, suggesting potential gluten sensitivity.

Conclusions:

• Passive small intestinal permeability is typically normal in atopic eczema and psoriasis.
• Defective intestinal integrity is unlikely to be a primary factor in the pathogenesis of eczema.
• Elevated intestinal permeability may be an early indicator of gluten-sensitive enteropathy in dermatitis herpetiformis, potentially preceding histological changes.