Allergies 2/2: the concrete levers for reducing the load

📌 This is Part 2 of our two-part series on allergies. In Part 1, we covered what happens in the body during an allergic reaction: IgE production, mast cell activation, histamine release, and the biological terrain that shapes how intense symptoms become. Here, we look at the concrete levers to reduce the load.

An allergy is not simply a matter of exposure. The allergen triggers the reaction, but the intensity of symptoms can also be influenced by context: mucosal barrier quality, exposure to irritants, sleep, indoor environment, and certain individual factors. Other factors such as diet, the microbiome, or certain hormonal parameters are still being actively researched.

The goal is not to find "the miracle supplement." The goal is to reduce the overall load: fewer allergens, fewer irritants, less unnecessary inflammation, and better support for the systems that regulate the response.

1. Identifying what's actually triggering the reaction

We often talk about "allergies" as though they all work the same way. In practice, triggers differ and so does their management.

| Trigger | Where to find it | | --- | --- | | Pollens | Outdoor air, clothing, hair, laundry dried outside | | Dust mites | Bedding, mattresses, pillows, carpets, textiles, dust | | Mould | Damp rooms, bathrooms, ventilation systems, walls, plant soil | | Pet dander | Sofas, clothing, carpets, bedding | | Dust / particles | Indoor air, pollution, cleaning, textiles | | Other irritants | Fragrances, candles, sprays, smoke, household products |

The first step is to map: when symptoms appear, where they are most intense, what makes them worse. Indoors or outdoors, day or night, by season, environment, activities, and sometimes individual factors. A dust mite allergy is not managed the same way as a pollen-related rhinitis.

2. Reducing exposure: a major lever, often underused

In many individuals, reducing exposure can decrease the frequency or intensity of symptoms. Reducing exposure does not mean living in a bubble. It means avoiding unnecessarily keeping the immune system in a state of alert.

| Situation | Useful actions | | --- | --- | | Pollens | Keep windows closed during peak times, avoid drying laundry outside, wash hair in the evening, change clothes when coming home | | Dust mites | Wash sheets and pillowcases at 60°C when possible, reduce accumulated textiles, vacuum with an appropriate filter, consider anti-mite covers if allergy is confirmed | | Mould | Address excess humidity, clean at-risk areas, check ventilation | | Pets | Keep them out of the bedroom, regularly wash textiles and throws, vacuum contact areas | | Dust / particles | Damp cloth rather than feather duster, HEPA vacuum cleaner, reduce dust-accumulating textiles | | Irritants | Limit indoor fragrances, candles, sprays, aggressive cleaning products, smoke |

For pollens, warm, dry, and windy days are often the most problematic. After heavy rain, concentrations may temporarily drop, though the resulting humidity can encourage mould growth in some profiles. The bedroom deserves particular attention: this is where exposure can last several hours, during the period when the body should be recovering.

3. Supporting the mucous membranes

The nasal, ocular, and respiratory mucous membranes are the first interface with allergens. If they are dry, irritated, or inflamed, their reactivity increases and the physical barrier they form may be less effective.

Nasal saline irrigation is one of the simplest and best-documented interventions in allergic rhinitis. It mechanically removes allergens, mucus, and irritants deposited on the mucosal surface.

| Option | Use | | --- | --- | | Saline spray | Daily maintenance, mild symptoms | | Nasal rinse (bottle / neti pot) | Congestion, post-outdoor exposure, heavy exposure | | Isotonic saline | Often better tolerated for regular use | | Hypertonic saline | May help with congestion, but can irritate some mucosae |

Best used after coming in from outdoors, before bed, or before a nasal spray advised by a healthcare professional. Important note: use sterile water, boiled and cooled, or water specifically intended for this purpose. Never use tap water directly.

4. Existing treatments

Terrain-based levers do not replace validated treatments in moderate to severe forms. They complement them. Here are the main options, to be discussed with a doctor or pharmacist according to symptom severity:

| Option | Primary target | | --- | --- | | Oral antihistamines | Sneezing, itching, runny nose | | Intranasal antihistamines | Nasal symptoms with rapid action | | Intranasal corticosteroids | Reference treatment for moderate to severe allergic rhinitis | | Antihistamine eye drops | Red eyes, watering, itching | | Allergen immunotherapy | Long-term approach if allergen is identified and symptoms are significant | | Asthma assessment | If cough, wheezing, unusual shortness of breath or respiratory discomfort |

5. Dietary histamine: relevant for certain profiles

In some people presenting symptoms consistent with poor tolerance to certain histamine-rich foods, a short and supervised dietary adjustment may be worth discussing. This approach is not, however, a standard treatment for respiratory allergies.

| Foods to temporarily limit | Why | | --- | --- | | Alcohol, especially wine and beer | May increase histamine load and reduce tolerance | | Aged cheeses | Higher histamine content | | Cured meats | Biogenic amines, preservation process | | Smoked, tinned, or poorly stored fish | Histamine linked to preservation | | Fermented foods: kombucha, sauerkraut, kimchi, vinegar | May worsen certain profiles | | Long-stored leftovers | Histamine increases with storage time |

This is not a lifelong elimination. It is a short and targeted strategy, to be used if the clinical picture justifies it, then reassessed.

6. Nutrition: supporting the inflammatory terrain

Diet does not act directly as an antihistamine. It acts on the terrain in which the allergic reaction occurs: baseline inflammation, microbiome, mucosal integrity, antioxidant status, and the production of immune-modulating metabolites.

| Priority | Concretely | | --- | --- | | Fermentable fibre | Varied vegetables, legumes if tolerated, wholegrains, whole fruits | | Dietary omega-3s | Sardines, mackerel, anchovies, salmon, walnuts, flaxseeds or chia | | Polyphenols | Berries, onions, capers, apples, green tea, cacao, aromatic herbs | | Dietary vitamin C | Kiwi, peppers, citrus fruits, broccoli, red fruits | | Sufficient protein | Tissue repair, enzymes, glutathione, immunity | | Fewer ultra-processed foods | Less sugar, additives, oxidised oils, lower nutritional density |

Fermentable fibres allow the microbiome to produce short-chain fatty acids (SCFAs), including butyrate. These metabolites contribute to maintaining the intestinal barrier, immune regulation, and the modulation of inflammation. Dietary omega-3s contribute to the production of pro-resolution mediators. Polyphenols have documented effects on inflammation and oxidative stress.

In practice: more varied vegetables, whole fruits, legumes if tolerated, oily fish, herbs and spices and fewer ultra-processed foods.

7. Supplements: only if the mechanism fits the profile

Supplementation may help certain profiles, but must remain targeted. The right supplement depends on the dominant mechanism.

| Supplement | Mechanism | When to consider it | | --- | --- | --- | | Quercetin | Mast cell modulation, histamine and cytokine inhibition observed in some studies | Marked histamine or mast cell-driven symptoms | | Vitamin C | Antioxidant, supports histamine metabolism, mucosal support | Diet low in plant foods, high histamine load | | Exogenous DAO | Degradation of dietary histamine in the small intestine | Evidence still limited; there is currently no standardised test to diagnose histamine intolerance | | Vitamin D | Immune regulation | Confirmed insufficient levels, inflammatory terrain | | Probiotics | Microbiome, intestinal barrier, immune modulation | Allergies with digestive symptoms, suspected dysbiosis; results vary depending on strains | | Omega-3s | Anti-inflammatory / pro-resolution lipid terrain | Low dietary intake or low omega-3 index |

Stacking supplements without an identified target makes no sense. This information is provided for educational purposes: supplementation should always be discussed with a healthcare professional based on your individual situation.

8. Sleep and physical activity

Sleep and stress modulate inflammation, immune reactivity, symptom perception, and recovery. During allergy season, a common vicious cycle develops: allergy, nocturnal congestion, fragmented sleep, increased inflammation, more intense symptoms the next day.

For the night, the most useful levers are straightforward: shower before bed, nasal rinse, filtered room air if needed, windows closed during pollen peaks, regular laundry washing, limited alcohol in the evening, consistent sleep schedule.

Physical activity remains beneficial for immune regulation, metabolic health, circulation, respiratory capacity, and baseline inflammation. What needs to be adapted is the exposure: avoid long outdoor sessions during pollen peaks or pollution spikes, favour indoor exercise if symptoms are significant, shower and change clothes after outdoor activity.

9. When a biological terrain assessment can help

Not everyone needs a comprehensive panel for occasional allergies. But if symptoms are severe, persistent, atypical, associated with other signs, or difficult to manage despite standard measures, an assessment can help understand what is amplifying the reaction.

Useful tests depend on the clinical context. When allergy is suspected, relevant markers may include: full blood count (for eosinophils), prick tests, or specific IgE. Depending on the picture, additional tests may be discussed to investigate associated or differential diagnoses.

The goal is not to test everything. It is to understand why the system is reacting so strongly, and where to act first.

To close

An allergy involves an identifiable immune response. But its intensity also depends on the context in which that response occurs.

Reducing exposure, supporting the mucous membranes, improving indoor air quality, lowering the histamine load where the profile warrants it, nourishing the microbiome, protecting sleep, correcting nutritional deficiencies: it is the combination of these levers, not any single one, that often makes allergy seasons more manageable.

There is no magic lever. There is a hierarchy: identify the triggers, reduce the load, support the mucosae, treat appropriately when needed, then individualise according to the terrain.

🎧 New episode on our podcast: Allergies, what if they're the sign of silent inflammation?

You sneeze in spring and tell yourself it's "just a little allergy." And yet: eczema that keeps coming back, food intolerances, reactions that worsen year after year, diffuse fatigue. What if your allergies were only the visible part of a silent inflammation, built up over years by your lifestyle? It is estimated that by 2050, one in two people will be allergic. In this new episode, Dr Anne-Sophie Darrigade, dermatologist, allergist and immunologist in Bordeaux, breaks down what's really going on.

Scientific references

1. Bousquet J, et al. Next-generation ARIA guidelines for allergic rhinitis. J Allergy Clin Immunol. 2020;145(1):70-80.

2. Folkerts J, et al. Effect of dietary fiber and metabolites on mast cell activation. Front Immunol. 2018;9:1067.

3. Head K, et al. Saline irrigation for allergic rhinitis. Cochrane Database Syst Rev. 2018;6:CD012597.

4. Luo C, et al. The efficacy and safety of probiotics for allergic rhinitis. Front Immunol. 2022;13:848279.

5. Maintz L, Novak N. Histamine and histamine intolerance. Am J Clin Nutr. 2007;85(5):1185-1196.

6. Trompette A, et al. Gut microbiota metabolism of dietary fiber influences allergic airway disease. Nat Med. 2014;20(2):159-166.

7. Yamprasert R, et al. Ginger extract versus loratadine in the treatment of allergic rhinitis. BMC Complement Med Ther. 2020;20:119.

The information in this article is provided for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional before making any changes to your diet, supplementation, or medical care. Lucis is not a medical device.