History Matters Friday, April 28, 2023
Hay fever
INTRODUCTION
In Kansas, many people have nasal congestion, watery eyes, sneezing, a little sore throat and a cough—and wonder if they are coming down with a cold or if it is “just their allergies acting up”. How does one tell? This brings us to the interesting history of “hay fever.”
I. HISTORY
- Dr. John Bostock in 1819, is the first to present a paper to the Medical Society of London with the title, Case of the Periodical Affliction of the Eyes and Chest in which a “patient” called JB (it was him) had itching and sneezing only during summer months. After trying opium, blood-letting, cupping, and mercury with no benefit, he found that only a 40 day quarantine seemed to help. He called the condition “summer catarrh” (eg. summer inflammation).
- 1829- the term “hay fever” is used in which the smell of hay inflames the body. There is inflammation but no fever associated with “hay fever.”
- 1860-Manchester physician, Charles Blackley (does not go by “Sir Charles”) identifies pollen as the culprit of “hay fever”.
- 1911 - Leonard Noon and John Freeman attempt allergy immunotherapy.
- 1913- “hist-amine” - an ethyl amine found in tissues (histo)
- 1930- Histamine type I receptors (and H1 blockers) found- discovered
- as cause of anaphylactic reactions.
- 1950- topical steroids introduced
II. POLLEN
- Male portions of plants, grasses, trees send their seed typically carried by wind or insects (occasionally mites or birds). It is basically flying plant sperm (sorry but true).
- Pollen actually has a “non-reproducing portion” with a wax and protein covering to protect it from getting dried out or burned up in the radiation of the sun; and then reproducible cells which are transferred into the pistil or female cone where the pollen travels into the ovule of the female plant, tree, grass.
- Pollen has enormous variety with apertures called colpi, sulci, and pores. The airborne pollen are light and float. The pollen transferred by insects is heavier and stickier. The study of pollen is palynology.
- Pollen counts are higher when it is windy, dry, and warm. Flowers and trees tend to be spring; grass (and hay) tends to be summer and ragweed tends to be fall, but there can be considerable variability.
- Bees are best known as the insects that carry pollen, but there are many hymenoptera and other insects which carry pollen as well as ants, spiders, mites, butterflies, beetles, fungi, bats and hummingbirds.
- “Bee pollen” is often sold as a “dietary supplement”- the actual chemical in pollen is p-coumaric acid which is an anti-oxidant and is naturally bactericidal -and found in other plants. There is no data to suggest this has any scientific benefit for humans (and why no legal claim can be made). Bee pollen is often contaminated with pesticides; and the pollen traps used to extract this from bees is a breeding ground for parasites which can be devastating to bee populations. There is little oversight to maintain any veracity or purity of “bee pollen”.
III. HISTAMINE
- There are 23 different physiological functions mediated by histamine with four different histamine receptors found in the body :
- H1 on mast cells, the brain, the gut responsible for:
- itching
- hyperpermeability (nasal congestion, eyelid swelling)
- hyper secretion (runny nose)
- neural hypersensitivity (sneezing)
- vasodilatation (anaphylaxis)
- wakefulness/irritability (neurons in hypothalamus- dorsal raphe))
- contracts bladder and smooth muscles
- enterochromafifin-like cells (ECL) - release stomach acid
- H2 found predominately in the stomach increases gastric secretion from parietal cells
- H3 in the brain (antagonists causing wakefulness)
- H4 regulate immune responses & regulate release of white cells
(similar to H3 but not as active in the brain)
A. Mast Cells
There are in your tissues and blood vessels which “stand guard” to be ready for infection, inflammation, trauma, or any form of foreign invasion. When pollen enters your nose and gets into blood stream. Your immune system does not know it. But a part of your immune system creates IgG as a type of “identification badge” for a foreign visitor. The IgG becomes a “sentry” on your mast cell. The first season a person moves to a new geographical area (or the first year of life in a human being), they may have a “honeymoon period” where their allergies don’t exist or don’t bother them (because their IgG has not yet “carded” the new pollens in that geographic region). Unfortunately subsequent seasons may be just as bad as their “normal allergies”. Places like Arizona used to be great for allergy sufferers but with so much irrigation and grass planted there now, this is no longer as true. So the pollen alerts the IgG anti-body on the surface of the mast cell which then releases histamine into the blood stream.
B. Other histamine releasing products
Histamine release does not have to be allergic. Morphine has a fair amount of histamine release which is why it causes flushing, drop of blood pressure, itching, vomiting, rash. This is not allergy. Hydromorphone (Dilaudid) and fentanyl have much less histamine release compared to morhine. So, fentanyl or hydromorphone are preferred to IV morphine. Polymixin B (neosporin) tends to cause histamine release and why one should avoid it for eye drops, using something like erythromycin ointment instead. Sake and wine can cause this same histamine flush for predisposed individuals.
IV. Physical Symptoms of histamine release
- EYES-The swelling of the lower eyelid creates a shadow which makes it look like there are dark circles under the eyes. (This same phenomenon occurs during some illness which mothers call “sick eyes”). The eyes may be red from vasodilation of the vessels. There may even be areas on the white part of the eyeball that look like they have water blisters on the eyeball. This is called “chemosis” and is the hyper permeability from the histamine.
- NOSE- Swelling of the inside of the nose makes it congested and makes it difficult to breath through it. Simultaneously, the nose runs due to hyper secretion. The inside of the nose can be very red or even blue and boggy from pooled venous blood and swelling. The eyes, nose, and throat are essentially one room with three partitions so one can see a swollen drippy uvula sometimes so big or long that people choke on it.
- Everywhere else- With what you can see in the eyes, nose, and throat—imagine this happening at the membranes and linings of the bronchus in the lungs, the lining of the stomach (causing vomiting and even diarrhea), the capillaries of the skin causing hives that can look like swollen geographic mounds. And the sin qua non is ITCHING and SWELLING from histamine release.
- “Hay fever” is a subset of seasonal allergies to grass (of which there are many different kinds). Seasonal allergies include allergic reactions to grass, plants, flowers, and trees—and are a subset of all kinds of animal, mold, food, drug, that can cause an allergic reaction. But histamine is the common denominator for all allergic reactions including seasonal allergies. There is no fever with “hay fever.” And “colds” don’t typically have itching and swelling to the eyes (though a large percentage of viral illnesses may actually be responsible for urticaria).
V. PREVALENCE
- 10-40% of US has seasonal allergies depending upon geography
- More common with children than adults (15% of teens)
- Seasonal allergies do not occur in the first year of life.
- Increased risk with eczema, milk/protein/peanut allergy/asthma
- Should not be called a “sinus infection” & be given antibiotics; it does not matter what the color of the snot is or whether “a Z-pak has helped you in the past—which would be the wrong antibiotic to use if there was such a thing as a”sinus infection”. This is the recommendations of the American Academy of ENTs: antibiotics are currently NOT recommended for any common sinus issues.
VI. TREATMENTS for SEASONAL ALLERGIES
- Histamine 1 Blockers (first generation)
Anti-histamines block histamines at preferred tissues causing less itching, decreased nausea, decreased anxiety, as well as increasing sedation because they are lipophilic and cross the blood-brain barrier.
- diphenhydramine (“Benedryl”) (US preparation) - it blocks histamine release but also can cause sedation and urinary retention (why it’s avoided in elderly)
- chlorpheniramine (OTC antihistamine -in cough & cold meds)
- clemastine (OTC antihistamine in cough & cold meds)
- bromopheneramine (OTC antihistamine in cough & cold meds)
- hydroxyzine (Vistaril) - prescription even more sedating to the point it is sometimes used for anxiety (anxiolytic)
- doxylamine (Unisom) - OTC med for insomnia- used for its sedation as well as combining with B6 in pregnancy for nausea.
- promethazine (Phenergan) prescription anti-emetic
- dimenhydrate (Dramamine)- OTC anti-emetic for motion sickness
- meclizine (Bonine) OTC anti-emetic and sedative for vertigo
- cyproheptadine (Periactin) pediatric migraine (nausea)
*the sedative properties in first generation antihistamines can paradoxically "wire" kids who have ADHD. It "puts frontal lobe to sleep" which worsens "executive function" (decision-making)
- Ketoprofen (Zaditor) eye drops
- Any eye drops that have A (will have an antihistamine)
2. Histamine I Blockers (second generation) -“non-sedating”
* lipophobic so does not cross the blood-brain barrier well.
- cetirizine (Zytec)
- loratadine (Claritin) - helps acne by decreasing glandular secretion
- fexofenadine (Allegra)
- desloratadine & levocetirizine are simply isomers used to keep their patents alive when the original drugs went generic.
3. Histamine -2 Blockers
- famotadine (Pepcid)
- ranitadine (Zantac) - currently off market
4. Topical Steroids -intranasal (OTC)
- triamcinolone (Nasacort)
- fluticasone (Flonase)
- budesonide (Rhinocort)
5. Topical Decongestants- intranasal
- oxymetazoline (Afrin)
- phenylephrine (Neo-Synephrine)
* For immediate itching and swelling from seasonal allergies, take a first generation anti-histamine (depending on whether you want sedating or non-sedating , but equally effective to block histamine). If your nose is badly congested, you can use a topical nasal decongestant off and on for a few days for temporary relief. If you have frequent nasal congestion, stop the decongestant and use daily intranasal steroid (keep beside your tooth brush to use daily when you brush teeth). It is prevention and will NOT provide immediate relief. For bad allergy sufferers, daily intranasal steroids, and as needed oral antihistamines and/or antihistamine eye drops.
VII. Non-pharmacologic approaches
- Neti pots - rinsing with nasal saline may provide benefit. However, if one uses tap water or the water is stagnant; one can actually do harm by introducing molds or protozoa.
- Sunglasses -wrap around have support for decreasing eye symptoms
- Allergy purifiers - one can find filters for car and home which have proof of trapping pollen with HEPA filters. HEPA filters - High Efficiency Particulate Air filter can reduce pollen. Filters that have a Clean Air Delivery R (CADR) of over 300 and even better at >350; as well as a MERV (Minimum Efficiency Reporting System) that is high (listed from 1-12) are all excellent to filter pollen—and the higher the ratings; the higher the cost. Unfortunately, collecting lots of pollen in filters in your car, office or home may not translate into less symptoms. Pollen can be on the vents, the carpet, your hair from being outside. It is an assumption, possibly wrong, that high dollar HEPA filters help your allergies, even though they may collect a lot of pollen. They may be a surrogate marker that makes no clinical difference in an individual.
- slip-covers- these are primarily for mites on pillows (not for pollen) and have not shown to be of benefit
- Eating honey does not reduce allergic symptoms.