Hazel (Tree)

Description

Hazel trees (Corylus species) are deciduous shrubs or small trees recognized for their rounded leaves and production of edible hazelnuts. Commonly found in woodlands, hedgerows, and urban areas, hazel trees are native to Europe and parts of Asia. They are often used in coppicing and are valued for their flexible branches and nuts.

Allergy Symptoms

Exposure to hazel pollen can cause allergic reactions, including:

• Nasal symptoms: Sneezing, runny or congested nose.
• Ocular symptoms: Itchy, watery, and red eyes.
• Respiratory issues: Coughing and exacerbation of asthma symptoms.

Hazel pollen contains allergens such as Cor a 1, which is related to the Bet v 1 allergen found in birch pollen. This means individuals allergic to birch pollen may also react to hazel pollen due to cross-reactivity.

Typical Pollination Period

Hazel trees are among the earliest to pollinate, with periods varying by region:

• United Kingdom: Pollination can begin as early as January, peaking between February and March.
• Other regions: Timing may vary based on local climate conditions but generally occurs in late winter to early spring.

Geographic Distribution

Hazel trees are widely distributed across:

• Europe: Common throughout, especially in woodlands and hedgerows.
• Asia: Found in parts of Asia, including regions of China and Japan.
• North America: Some species are present, though less prevalent.

Tips for Reducing Exposure and Managing Allergies

• Monitor pollen forecasts: Stay updated on local hazel pollen levels during the pollination season.
• Limit outdoor activities: Especially on high pollen count days and during morning hours when pollen levels are typically higher.
• Protect indoor environments: Keep windows closed and use air purifiers to reduce indoor pollen exposure.
• Personal hygiene: Shower and change clothes after being outdoors to remove pollen.
• Medication: Use antihistamines, nasal corticosteroids, or other allergy medications as recommended by a healthcare professional.
• Consult an allergist: For persistent or severe symptoms, seek advice from an allergist who may recommend immunotherapy or other treatments.