Possible causes: eczema, hives, contact allergy, irritant dermatitis, infection, medication effects or heat. Flushing can also occur with hormonal changes or autonomic symptoms.

One step: photograph a changing rash and note timing, products and medicines. Seek care for a painful, blistering or rapidly worsening rash.

Possible causes: allergic rhinitis, a respiratory infection or non-allergic rhinitis triggered by irritation or temperature changes.

One step: note whether symptoms follow pollen, dust, fragrance or illness. Persistent symptoms deserve assessment.

Possible causes: asthma, infection, irritation, reflux or inducible laryngeal obstruction (sometimes called vocal cord dysfunction). Sudden symptoms can be anaphylaxis.

One step: follow your prescribed action plan. Severe or rapidly worsening breathing symptoms need urgent help.

Possible causes: food allergy, intolerance, coeliac disease, IBS, reflux, infection or inflammatory bowel disease.

One step: record the food, timing and symptoms. Avoid broad food exclusions without dietary support. Do not try a suspected serious allergen at home.

Possible causes: infection, inflammatory disease, anaemia, thyroid problems, sleep disorders, medication effects or post-viral illness.

One step: discuss persistent or changing symptoms with a clinician. With PEM, account for delayed worsening after effort.

Possible causes: autonomic problems, dehydration, medicines, heart conditions or a systemic allergic reaction. Swelling also has non-allergic causes.

One step: note whether symptoms follow standing, a medicine or an exposure. Sudden tongue/throat swelling, breathing difficulty or collapse is an emergency.

NIH foundation: reduce harmful exposures and address relevant allergens.

Try: choose a tolerated cleaning product or ask for a smoke-free space.

Make it fit: fragrance-free does not guarantee tolerance. Address dampness and leaks; get help if cleaning worsens symptoms.

May also help: sensory comfort, migraine or respiratory symptoms.

NIH foundation: support nutrition and hydration.

Try: make a tolerated meal and drink easy to reach.

Make it fit: use a dietitian for multiple restrictions. A low-histamine diet is not required for everyone. Coeliac testing is affected by avoiding gluten; discuss testing before changing intake.

May also help: energy and digestive comfort.

NIH foundation: support sleep and recovery.

Try: simplify one task or arrange a recovery pause.

Make it fit: address night-time itch, breathing symptoms or pain with your clinician. With PEM, avoid pushing through or fixed activity increases.

May also help: pain, mood and coping.

Try: keep prescribed medicines and action plans accessible.

Make it fit: review side effects, interactions and technique with a pharmacist or clinician. Some antihistamines cause sedation. Do not change doses without appropriate advice.

May also help: sleep and participation when symptoms improve.

NIH foundation: use prevention measures such as hand hygiene and recommended vaccinations.

Try: keep handwashing supplies accessible and discuss your vaccination needs.

Make it fit: immunosuppressive treatment may change vaccine advice and when to seek care for infection. Follow your team’s guidance.

May also help: protect energy by reducing avoidable illness.

NIH foundation: prioritise demands and draw on supportive relationships.

Try: ask for help with a meal, shopping or an appointment.

Make it fit: explain your needs briefly. You do not need to prove a mechanism before requesting a reasonable adjustment.

May also help: anxiety, mood and sensory load.

Allergic rhinitis, food allergy, asthma and eczema may occur together. Not all asthma or eczema is driven by a specific allergy.

Recurrent hives or swelling need assessment. Causes and treatments differ; throat or tongue swelling can require emergency care.

Consensus MCAS assessment considers recurrent systemic episodes, objective evidence of mediator release and response to appropriate treatment, while investigating alternatives.

Feeling better with an antihistamine does not by itself confirm MCAS. MCAS and mastocytosis are different diagnoses.

Examples include coeliac disease, rheumatoid arthritis and inflammatory bowel disease. Persistent joint swelling or other unexplained symptoms may warrant targeted assessment.

No single inflammation test identifies every condition.

Food intolerance differs from food allergy. Non-allergic rhinitis, reflux, migraine or airway irritation may also contribute to reactions.

Assessment can guide useful adjustments without assuming an immune cause.

Damp buildings can affect respiratory health. Repair moisture problems and assess asthma, allergy or irritation.

Symptoms attributed to CIRS or chemical sensitivity deserve care. Proposed CIRS tests and treatment protocols are not established routine care; urine mycotoxin tests do not reliably establish illness from indoor mould.

Reactions, autonomic symptoms and anxiety can each involve palpitations or dizziness. Fear can follow frightening reactions. Do not dismiss breathing difficulty or collapse as anxiety.

Hypermobility and allergic or mast cell symptoms can coexist. The proposed hEDS–POTS–MCAS connection does not establish one mechanism or diagnose any of these conditions.

Inflammatory conditions can cause pain. Migraine, nerve pain and other pain conditions may also coexist without being autoimmune or allergic.

Persistent symptoms, sleep disruption and restrictions can affect mood. Emotional support can accompany medical care; trauma is not an assumed cause of immune disease.

A scent or texture may be difficult because of sensory needs, irritation, migraine or allergy. Adjustments can help while the relevant cause is assessed.