Nettle / Pellitory

Nettle family plants (Urticaceae) are significant pollen producers that are often overlooked as allergens. Pellitory (Parietaria) is particularly important in Mediterranean climates and coastal areas. These plants produce small, inconspicuous flowers that release lightweight pollen in enormous quantities. The sting of stinging nettle is caused by histamine and formic acid in the plant's hairs — completely separate from the pollen allergy.

If you're allergic to nettle / pellitory pollen, you may also react to:

• Other Urticaceae family plants
• Mulberry (same order Rosales — limited)

• Nettle pollen is extremely small, making it highly respirable — it reaches deep into the lungs more easily than larger pollens.
• Pellitory grows on walls and in cracks — it's an urban allergen that thrives in cities.
• The stinging sensation from touching nettles is unrelated to pollen allergy.