Current evidence from clinical trials does not support the use of antihistamines in routine eczema management, according to researchers.
Adding oral antihistamines to existing eczema treatments was found to be unlikely to lead to significant reductions in eczema and itch severity, and may not reduce sleep disturbance or flare-ups.
“Our findings do not support their use in routine atopic dermatitis management”
Study authors
In addition, some antihistamines may actually increase side effects such as drowsiness and the risk of patients stopping treatment, according to the authors of a review from Canada and the US.
They said their review, published in the British Medical Journal this week, addressed longstanding uncertainty on the role of antihistamines in treating atopic dermatitis, commonly known as eczema.
They highlighted, however, that oral antihistamines were one of the most-commonly used drugs for managing eczema, with an estimated one in five UK patients using them.
Despite their widespread use, previous evidence of their benefits and harms in treating eczema had been inconclusive, noted the researchers, led by a team from McMaster University in Ontario.
As a result, they reviewed the results of 47 randomised controlled trials involving 6,230 children and adults – the average age was 20 and 52% were female – with mainly moderate to severe eczema.
The trials compared the effects of adding oral H1 antihistamines, H2 blockers, mast cell stabilizers, or their combinations to placebo – with or without background moisturisers or steroid creams.
The various trials looked at treatment effects on eczema severity, itch severity, sleep disturbance, flare-ups and quality of life, as well as harms such as sedation and drowsiness.
Overall, the systematic review found H1 antihistamines might result in a small but clinically unimportant reduction in eczema and itch severity, and may not reduce sleep disturbance or flare-ups.
First generation antihistamines also probably increase cognitive impairment such as sedation and drowsiness, and may increase the risk of stopping treatment due to side effects, the review found.
The researchers said: “This systematic review and network meta-analysis addresses the longstanding uncertainty surrounding the role of antihistamines in treating atopic dermatitis, showing they likely do not meaningfully improve patient important outcomes while probably increasing harms.”
The authors stated: “Our findings do not support their use in routine atopic dermatitis management.
“We have provided a foundation for an evidence-based change in practice, supporting the development of updated atopic dermatitis guidelines that prioritise efficacy, safety, and patient centred care.”
The study received funding from the American Academy of Allergy, Asthma & Immunology, and American College of Allergy, Asthma and Immunology.