An older woman, with known allergic rhinitis, started daily morning smoothies containing powdered hemp protein, fermented goats milk, maca, kiwifruit, cashews and bee pollen.

Dr Meilyn Hew, Immunologist and Allergist, Murdoch

Within a few minutes of her first smoothie she developed itching hands, facial swelling, nasal congestion, breathlessness, and generalised hives.

Skin testing was negative to all components of the smoothie except bee pollen. Further testing showed significant reactions to grasses and tree pollens. Her diagnosis was acute anaphylaxis in an aeroallergic patient following ingestion of aeroallergen in bee pollen.

Pollen, the male germ from a flower, is the major source of protein for honeybees. Called “bee pollen”, it is high in plant pollen, dependent on the available plants and may be contaminated with insect body parts, fungi, bacteria and bee faecal material. It is held together in granules with honey. Its use as a protein nutritional supplement has increased.

There is also potential risk for allergy with honey given it can have pollen contamination, and royal jelly. It is unclear whether all patients with aeroallergen sensitivity need to avoid all bee products.

Skin test reactivity to common aeroallergens especially mug wort, olive tree and grasses correlates with reactivity to bee pollen granules

This patient was significantly sensitised to pollen aeroallergens though with little aeroallergy symptoms. One gram of bee pollen (approximately half a teaspoon) is estimated to contain between 0.4-6.4 x 10^6 plant pollen. Two to three tablespoons used in the smoothie would represent high oral pollen intake.

Increasing use of dietary supplements in Australia increases the incidence of allergic reactions to these products. Numerous herbal medicines are derived from plants particularly of the Asteraceae family, (common flowering plants) which often cause allergic rhinitis and asthma.

Patients with sensitization to Asteraceae pollens may present with allergic reactions to plant-derived complementary and alternative medicines (CAM). These can be minor oral allergy symptoms due to plant cross-reactivity, or more severe including anaphylaxis (see Table).

When using subcutaneous or sublingual allergen-specific immunotherapy, concentrated allergen induces tolerance. Doses are gradually increased to reduce acute allergic reactions including anaphylaxis. There are reports of some patients having anaphylaxis from taking unconventional treatment containing bee pollen to treat allergic rhinitis, especially when commencing at high levels.

Some authors suggest patients with pollen allergy be advised of the potential risk when consuming pollen products. This patient did not realise the significance of the general allergy warning on the label until her assessment. She now avoids bee pollen, but continues to tolerate honey.

Key Messages

  • Allergies to natural products are increasing with increased consumption.
  • Labelling may not always be helpful.
  • Patient advice needs to be individualized.

Table: Examples of Asteraceae flowering plants and possible cross-reactivities

EDIBLE PLANTs FLOWERING PLANTS WEEDS CAM
Lettuce

Safflower

Artichoke

Chicory

Daisies

Chrysanthemums

Marigolds

Sunflowers

Dahlias

Ambrosia spp (e.g. Ragweed)

Artemisia spp (e.g. mug wort, wormwood)

Parthenium (feverfew)

Echinacea

Dandelion

Chamomile

Feverfew

Wormwood

Milk thistle

Author competing interests: nil relevant. Questions? Contact the editor

Disclaimer: Please note, this website is not a substitute for independent professional advice. Nothing contained in this website is intended to be used as medical advice and it is not intended to be used to diagnose, treat, cure or prevent any disease, nor should it be used for therapeutic purposes or as a substitute for your own health professional’s advice. Opinions expressed at this website do not necessarily reflect those of Medical Forum magazine. Medical Forum makes no warranties about any of the content of this website, nor any representations or undertakings about any content of any other website referred to, or accessible, through this website.

No more articles