MedWire News: There are numerous variants of the “allergic march,” with eczema followed by asthma and then rhinitis being the most common sequence, say UK researchers.

“The allergic march, which refers to the sequential progression of multiple atopic conditions in terms of their development and symptomatic manifestations, has been an area of considerable interest over recent years,” explain Aziz Sheikh (University of Edinburgh) and Y Punekar (Schering-Plough Ltd, Welwyn Garden City) in the journal Clinical and Experimental Allergy.

To investigate the most common sequential manifestations of allergic march, the researchers used the UK’s General Practice Research Database to study 24,112 children who were followed-up throughout childhood.

Overall, 52.1% of the children were diagnosed with at least one, 16.1% were diagnosed with at least two, and 2.5% diagnosed with at least three allergic conditions by the age of 18 years.

Analysis revealed that eczema was the most common index condition, with 60.7% of allergic children being diagnosed with this disease first.

Among children who were diagnosed with eczema first, the relative risks (RRs) for them then being diagnosed with asthma followed by rhinitis or rhinitis followed by asthma were 1.59 and 0.54, respectively.

For the 28.4% of allergic children who were diagnosed with asthma first, the RRs for them then being diagnosed with eczema followed by rhinitis or rhinitis followed by eczema were 1.27 and 0.27, respectively.

For the 10.5% of allergic children who were diagnosed with rhinitis first, the RRs for subsequently being diagnosed with eczema followed by asthma or asthma followed by eczema were 0.64 and 0.47, respectively.

Sheikh and Punekar conclude: “Among children diagnosed with multiple allergic diseases there is likely to be a number of variants of the allergic march. Of these, the diagnosis of eczema followed by asthma, which is in turn followed by rhinitis, is the most common trajectory.

“Surprisingly, some diagnoses indicate a possible strong protective effect of manifesting further likely allergic diagnoses.”

They add: “We hope [the findings] will prove to be helpful both clinically and also for those planning trials aiming to halt progression of the allergic march.”

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2009

Free abstract