Also known as the most common form of eczema, atopic dermatitis is a chronic pruritic skin condition that causes skin to become excessively itchy, dry, cracked, and discolored. Atopic dermatitis often begins in childhood but can also occur in adulthood. This condition occurs when the immune system becomes overactive, leading to inflammation that damages the skin’s barrier and leaves the skin more sensitive and vulnerable to irritants. However, it has been unclear why this immune dysregulation and overactivity occurs.

One hypothesis is that antibiotic exposure in infancy contributes to the gut dysbiosis and immune dysregulation that causes atopic dermatitis; therefore, antibiotic exposure could heighten the risk. Possible studies have hinted at a possible link, but conclusive evidence has remained elusive…until now.

Assessing the Risk of Atopic Dermatitis Development

The European Medical Journal (EMJ) discusses a study published in the Journal of Allergy and Clinical Immunology that:

aimed to elucidate the timing and specific factors mediating the relationship between systemic (oral or intravenous) antibiotic usage and AD.

This longitudinal general population birth cohort study included data from 7,076 individuals (3,621 mothers and 3,455 infants). To begin, the research team analyzed stool samples from the infants to identify where gut microbiota dysbiosis occurred and how often it occurred alongside atopic dermatitis. Findings from the study show that children given systemic antibiotics within their first 12 months of life had a higher risk of developing atopic dermatitis before or by age five. This was true regardless of what illness the children had that required antibiotic treatment. The study shares that:

Alterations in the 1-year infant gut microbiome of participants who would later develop AD included increased Tyzzerella nexilis, increased monosaccharide utilization, and parallel decreased Bifidobacterium, Eubacterium spp., and fermentative pathways.

However, children who received antibiotics after one year old did not have a more significant or increased risk of developing atopic dermatitis. This suggests that doctors should take caution with antibiotic prescriptions in early infancy given how sensitive infant microbiota is and how much development their bodies are going through.