Antihistamine Trial · Ade Whetton
Mast cell activation trial
Where the question has got to, what's still unmeasured, and a daily symptom log running across an unmedicated baseline week and the treatment period — with temperature recorded alongside, so a cooling August can't be mistaken for a drug effect.
Phase —
Days logged 0
Baseline avg —
Treatment avg —
Adherence —
Where this has got to For a GP appointment
Ade Whetton, 50. Written up 27 July 2026. Dr Gemma Lewis is Ade's partner and a GP, but not his GP — her input here is informal advice between partners, not clinical care. Everything requiring a request form or a prescription needs to go through Ade's own practice.
Current plan
Cetirizine 10mg three times daily — 14 days. Suggested informally 27 July 2026; cetirizine is
available over the counter and is being bought, not prescribed. Three times the licensed dose, which is
standard off-label practice for urticaria and mast cell work (guidelines support up to four times).
No H2 blocker at this stage.
Dose times 06:00 / 14:00 / 22:00 — 8-hourly, mapped onto Ade's actual day.
Baseline 27, 28 and 29 July unmedicated · treatment days 1–14 from 30 July · review 13 August.
Dose times 06:00 / 14:00 / 22:00 — 8-hourly, mapped onto Ade's actual day.
Baseline 27, 28 and 29 July unmedicated · treatment days 1–14 from 30 July · review 13 August.
Temperature control
Baseline deliberately spans the range — Met Office forecast 22°C, 27°C and 30°C for 27–29 July.
The 29th is the hottest day in the run, so it is being spent unmedicated: an untreated 30°C day is a
one-off observation, whereas a treated hot day is likely to recur inside the fortnight.
Visible treatment week averages ~25°C against a ~26°C baseline, which is inside the 2.5°C tolerance
this trial checks for. If week two turns hot, that understates any benefit rather than inventing one.
Symptoms driving it
Heat intolerance — long-standing and marked. Gut upset — recurrent.
These are the two Ade recognised without prompting. Described further on 27 July — see below.
Drenching night sweats
Soaking through three pillowcases nightly; changed and washed daily.
Priority
Described 27 July 2026. Primary focal hyperhidrosis characteristically ceases during sleep, so sweating of this volume while asleep points to a secondary systemic cause rather than constitutional "running hot". Accompanied by persistent subjective heat and increased irritability. Long-standing and well known to Gemma. Recorded here so the volume and the timing are written down alongside everything else, not because it is news.
Described 27 July 2026. Primary focal hyperhidrosis characteristically ceases during sleep, so sweating of this volume while asleep points to a secondary systemic cause rather than constitutional "running hot". Accompanied by persistent subjective heat and increased irritability. Long-standing and well known to Gemma. Recorded here so the volume and the timing are written down alongside everything else, not because it is news.
Unifying hypothesis
Thyroid. Heat intolerance, profuse sweating, irritability, fatigue and brain fog (Head 3/3),
palpitations and lightheadedness (Cardio 2/3), and a GGT of 106 that has no other explanation —
thyrotoxicosis raises liver enzymes. One test covers all of it.
Thyroid function has never been tested — confirmed by Ade, 27 July 2026. Not on the September 2025
panel and not anywhere else.
Also to exclude
Obstructive sleep apnoea — night sweats, fatigue and brain fog in a 50-year-old man; common
and treatable.
B symptoms — drenching night sweats warrant asking about unintentional weight loss, fever and lymphadenopathy. Asked 27 July, answers pending.
B symptoms — drenching night sweats warrant asking about unintentional weight loss, fever and lymphadenopathy. Asked 27 July, answers pending.
Testosterone
Never tested. Ade suspects it is low.Requested
Symptom overlap with thyroid disease and sleep apnoea is close to total — fatigue, brain fog, irritability, low drive. Night sweats are not a typical low-testosterone feature, which argues against it being the primary problem. Both untreated thyroid disease and OSA suppress testosterone, and testosterone therapy worsens OSA, so those want answering first. Testing requirements in the asks below.
Symptom overlap with thyroid disease and sleep apnoea is close to total — fatigue, brain fog, irritability, low drive. Night sweats are not a typical low-testosterone feature, which argues against it being the primary problem. Both untreated thyroid disease and OSA suppress testosterone, and testosterone therapy worsens OSA, so those want answering first. Testing requirements in the asks below.
Skin — what it is
Eczema, hands and wrists, six months. Not flushing and not urticaria. This is what the
Skin 3/3 daily score represents, and it is considerably less specific to mast cell activation than
urticaria would have been. Needs emollient and topical steroid on its own account. New hand and wrist
eczema at this age may have a findable contact or irritant trigger.
Hypermobility (5PQ)
0–1 out of 5Below threshold
Clear no to thumb-to-forearm, dislocations, childhood contortion and self-described double-jointedness. Possible yes to hands-flat-to-floor, but limited by hamstring tightness from deconditioning rather than joint range — the least specific item on the questionnaire. Threshold is 2.
Clear no to thumb-to-forearm, dislocations, childhood contortion and self-described double-jointedness. Possible yes to hands-flat-to-floor, but limited by hamstring tightness from deconditioning rather than joint range — the least specific item on the questionnaire. Threshold is 2.
Hitchhiker's thumb
PresentDoes not score
Photographed 27 July. Distal hyperextensibility at the thumb interphalangeal joint is a common anatomical variant and is not a Beighton or 5PQ item — it is a different joint from the thumb-to-forearm sign, which is negative. Noted here so it isn't carried forward as supporting evidence.
Photographed 27 July. Distal hyperextensibility at the thumb interphalangeal joint is a common anatomical variant and is not a Beighton or 5PQ item — it is a different joint from the thumb-to-forearm sign, which is negative. Noted here so it isn't carried forward as supporting evidence.
Outstanding
A full Beighton score in person. All five Beighton manoeuvres are passive — the examiner
takes the joint to end range. Self-testing consistently under-reads, because you stop where it feels
odd rather than at the anatomical limit. Sixty seconds in person replaces all of the above.
Alcohol
NoneExcluded
Removes the commonest benign explanation for flushing, palpitations and gut upset.
Removes the commonest benign explanation for flushing, palpitations and gut upset.
Serum tryptase
Never doneGap
The objective limb of the diagnosis. A raised baseline would also open up hereditary alpha-tryptasemia, which fits heat and gut intolerance without needing hypermobility.
The objective limb of the diagnosis. A raised baseline would also open up hereditary alpha-tryptasemia, which fits heat and gut intolerance without needing hypermobility.
GGT
106 U/L (range 10–71), down from 120 in Dec 2024Unexplained
Reported as "monitoring, trending down". In a non-drinker that needs a stated cause — most plausibly metabolic, given Dec 2024 triglycerides 4.57 and HbA1c 5.7%, both since normalised (1.07 and 5.3%). Worth naming rather than assuming.
Reported as "monitoring, trending down". In a non-drinker that needs a stated cause — most plausibly metabolic, given Dec 2024 triglycerides 4.57 and HbA1c 5.7%, both since normalised (1.07 and 5.3%). Worth naming rather than assuming.
Sept 2025 panel
Total cholesterol 4.99 · LDL 2.95 · HDL 1.5 · triglycerides 1.07 · HbA1c 5.3% · BP 130/77.
Cardiometabolically all in range after a substantial turnaround from Dec 2024.
Declared bias. Ade has been reading a lot about histamine and flags that
this may be shaping what he notices. That's the right worry to have — mast cell activation is one of
the most over-attributed labels going, and reading about it reliably produces symptoms to match.
It is the reason this is built around a no-medication baseline week, objective bloods and a
temperature control rather than around how he feels the trial is going. The onset section below
separates what predates the reading from what doesn't.
What to ask the GP for One appointment, one form
All of the bloods below can go on a single request. The only sequencing that matters is that the testosterone sample must be taken in the morning.
- Thyroid function — the priority TSH and free T4. Never tested. Potentially explains the heat, the sweats, the irritability, the fatigue, the palpitations and the unexplained GGT in a single result.
- Review the night sweats directly Volume and timing were not previously described. Worth the standard questions on weight, fever and lymphadenopathy, and a thought about obstructive sleep apnoea, rather than leaving it behind a two-week antihistamine trial.
- Testosterone — done properly, or not at all Never tested. Ade suspects it is low. Requires a morning sample before 11am, fasting, repeated on a second day if low — an afternoon sample reads up to 30% lower and is uninterpretable. Panel must include total testosterone, SHBG, LH, FSH and prolactin; without SHBG, free testosterone cannot be calculated and borderline results cannot be adjudicated. Below 8 nmol/L usually indicates treatment; 8–12 is the grey zone; above 12 does not. Note the order of operations: both untreated thyroid disease and obstructive sleep apnoea suppress testosterone, and testosterone therapy worsens sleep apnoea. Those want answering first — treating the cause may correct the testosterone without TRT.
- Serum tryptase on the same form Still worth having. Not affected by antihistamines, so timing against the trial doesn't matter. A raised baseline would also open up hereditary alpha-tryptasemia.
- Treat the eczema on its own account Emollient and topical steroid. Six months on the hands and wrists, possibly a findable contact or irritant trigger. Antihistamines will do little for it beyond the itch.
- Famotidine as the next lever if the gut doesn't shift Cetirizine at 30mg/day should cover the skin and general picture well. Gut symptoms run substantially through H2 receptors, so if everything else improves and the gut doesn't, that's the obvious next step rather than a failed trial.
- Beighton score in person, 60 seconds To settle the hypermobility question properly rather than on a self-scored questionnaire confounded by tight hamstrings.
If a bad flare happens at any point, that is the moment tryptase is worth
repeating — the diagnostic criterion is a rise of ≥20% + 2 ng/mL within 1–4 hours of an
episode, not the resting level.
Today's log
Score each domain 0–3. 0 none · 1 noticeable · 2 interfering with the day · 3 severe. Score how the day was overall, not the worst single moment.
Lie flat five minutes, take your pulse, stand up, take it again after three minutes standing still. A sustained rise of 30 bpm or more is the POTS threshold — this is the dysautonomia leg of the triad, and it is the one nobody ever measures.
Doses actually taken today
Night sweatsLast night. 0 none · 1 damp · 2 wet, one pillowcase · 3 soaked through
DrowsinessSide effect, not a symptom — scored separately, excluded from the total
Driving. Cetirizine sedates roughly one person in ten at the licensed dose, and
three times that raises the odds. Don't drive, and don't take on any driving work, until you know how a
full day at 30mg actually affects you — driving while impaired by a legal medicine is still an offence.
If drowsiness is a problem, that's the argument for asking the GP about fexofenadine at an equivalent
up-dose instead; it's the least sedating of the class.
Saved
Trend Total symptom score per day
Grey bars are baseline days, teal are treatment days. The amber line under each bar is that day's heat — if the teal bars only fall when the amber falls, the weather is doing the work, not the antihistamines.
Baseline
Treatment
Heat (peak °C)
Daily log
Onset — what predates the reading One-off
The cleanest defence against confirmation bias. Symptoms that were there long before you'd heard of any of this can't have been created by reading about it. Anything that only appeared afterwards should be treated with suspicion — by you and by whoever reads this. If a domain is scoring above zero in the daily log, it needs a real answer here rather than "unsure".
Mark each domain above.
Hypermobility & tryptase One-off
The 5-part questionnaire is scored on "now or ever" — joint range drops with age, so childhood counts. Two or more yes answers suggests generalised hypermobility. Pre-filled from Ade's answers on 27 July 2026; question 1 is marked yes on the generous reading.
Answer the five questions above for a score.
Ask the GP to add serum tryptase to the request form. Antihistamines do not interfere with it, so timing against the trial does not matter.
Summary for the GP Copy at end of trial
Regenerate this whenever you want the current picture. It compares baseline against treatment, adjusts for the temperature difference between the two periods, and flags if the trial is not yet long enough to read.
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