How Pollen Sensitisation Patterns Differ Between Africa and Europe

Atopic dermatitis (AD), commonly known as eczema, is a chronic inflammatory skin condition that often occurs alongside other allergic diseases like allergic rhinoconjunctivitis (ARC) and asthma. The triggers for these allergic conditions,  especially pollens, can vary widely depending on geographic region and local exposure.

A recent international study compared pollen sensitisation patterns in AD patients from Central Europe (Switzerland) with those from sub-Saharan Africa (Tanzania and Madagascar). Researchers tested blood samples from 90 participants (20 AD patients and 10 healthy controls from each region) using a comprehensive multiplex IgE allergy test.

Key Takeaways

1. Similar Rates of Asthma and ARC But Very Different Sensitisation Patterns

Although rates of asthma and ARC were similar among AD patients across all three regions, the patterns of what they were actually allergic to were very different.

2. European Patients Show Frequent Pollen Sensitisation

AD patients in Switzerland showed multiple sensitizations to grass and tree pollens, common triggers during spring and summer allergy seasons in Europe. These included allergens from grasses like timothy and rye, as well as tree pollens such as birch and hazel.

3. African Participants Had Fewer Sensitisation Results

In contrast, the study found almost no sensitisation to the tested grass pollen allergens in participants from Tanzania and Madagascar, even though many reported allergy symptoms like ARC. This suggests that the standard panels used in allergy testing may miss locally relevant pollens in sub-Saharan Africa.

4. What This Means for Allergy Testing in Africa

The results highlight an important gap in allergy diagnostics: commercial IgE testing panels are typically designed for temperate climates and may not reflect the pollen exposures most common in African regions. This means clinicians could underestimate or overlook key allergens in patients living there.

Tailored local allergy panels and more research into regional pollens are essential for accurate diagnosis and better treatment strategies for allergic diseases in different geographical settings.

Read the full open-access study here: Sensitizations to pollen differ between Central European and Sub-Saharan African atopic dermatitis patients