Clinical Cases

A Case of Tear Gas Poisoning

Homeopath Arden Wong presents a case of tear gas poisoning occurring in Hong Kong after a protest. Greenish expectoration, diarrhea, hot breath and sour perspiration were among the symptoms leading to the simillimum.

10th September, 2019.

Abstract:  This is a case of tear gas poisoning in Hong Kong solved with homeopathy, illustrating the application of the Hahnemann’s approach. It was repertorized with Boenninghausen’s Therapeutic Pocket Book (1846), and verified with primary-source materia medica.


Tear gas, therapeutic pocket book, case study, Hong Kong.

Chief complaint: 

Dyspnoea and diarrhoea after repeated exposures to tear gas (Homeopathy for Gas).

Case background:

The patient has been a first-aider in the many protests in Hong Kong in the previous two months since June 2019.  According to the police reports as of late August, nearly two thousand tear gas canisters were shot during many protests, including residential and commercial districts, as well as closed areas like subway stations, injuring many protesters, civilians, press, first aiders, and medical professionals.  Her previous experience of the tear gas has been mostly mild and transient with only skin and throat burning sensations, which disappeared in a few hours.  However, recently it’s been shown that expired tear gas cannisters were deployed which are reportedly causing extra irritation with longer duration and possibly delayed onset of symptoms.   This patient is one of them. She said the tear gas smelled different.  She had not sought conventional professional medical help because the doctors (especially public ones) often collude with the police. She had tried antibiotics as recommended by a nurse friend without any relief of symptoms.  Civilians and local medical professionals are concerned that some tear gas may contain cyanide due to decomposition over time or combustion at high temperature.


The first consult was conducted over the phone on Aug 2019. Collated details after homeopathic anamnesis:

  1. Causation:  Multiple exposures to tear gas / pepper spray (her symptomatology is consistent with those reported in the local press and medical professionals)
  2. Cough with profuse mucous accumulation, with green / yellowish expectoration only in the morning. None expelled at other times of the day.
  3. Dyspnoea is worse when lying on the back, better lying on the side or with the head high.
  4. Diarrhoea with pasty stool, liquid-like, dark brown in colour. No blood spotted so far.  Stool is often floating, and she said that any fatty foods are not tolerated.
  5. Appetite is much diminished, almost absent.
  6. Sporadic headache in the forehead described as stitching and boring inwards, a few times a day.  It occurs most typically a few minutes after rising from bed in the morning, or after lying down for a rest in the afternoon.
  7. Thirst is intense; especially craves cold drinks (by which she means room temperature) at up to 3-4 litres per day. She has a habit of adding some sea salt / Himalayan salt in her water – since before the intoxication.
  8. Urine is dark and frothy, but not turbid.
  9. Skin burning, red rashes were minimal and transient and not bothering her at present.
  10. Mouth tastes sour and burning, with hot breath.
  11. Sweat is also sour, and more profuse than usual.
  12. Palms are hot to touch, while she usually has chilly hands before.
  13. Dreams of protest scenes, being pursued (by unfriendly police), and violence.
  14. Generally feeling very ‘heaty’. Burning sensations from within ouwards.

Chronic health conditions are assumed irrelevant and omitted for privacy here.


  1. Schematic list of symptoms
Location Sensation Modalities  ~ worse Modalities ~ better
Respiration system Cough; expectoration green / yellowish Expectoration only in morning
Dyspnoea <  lying on the back;
<  with head low
> lying on the side;

> lying with head high

GIT Diarrhoea; Stool pasty, liquid-like, dark brown in colour; floating Fatty foods
Appetite – absent
Mouth Taste sour, hot
Thirst – intense (Desire for cold drinks)
Perspiration Perspiration – sour, sticky
Breath – hot
Forehead – inner Boring / stitching pain – from outwards inwards soon after rising from bed
Urine Dark & frothy
Dreams Protest scenes, pursued by unfriendly police.
  1. My impression of the patient: Generally, she is full of heat (breath, inside out, dark coloured urine, green expectoration) and sourness (breath, sweat). Specific symptoms include: cough is worse for lying on back, head low; with expectoration green, only in morning. We take these as ‘characteristic symptoms’ (based on the instructions from Aphorism 153 of the Organon of Medicine) and translate these into relevant rubrics in our primary repertory, Boenninghausen’s Therapeutic Pocket Book (1846), compilations of symptoms from primary materia medica, this will include:
  • Sensations and Complaints, Generalities, Pressing (Aching), from Outwards Inwards {821} [63]
  • Urine, Color, Dark {442} [75]
  • Aggravation, Situation and Circumstance, Lying, Head Low, with {2513} [19]
  • Respiration, Hot {579} [17]
  • Fever, Perspiration, Odor, Sour (Acidic) {2111} [28]
  • Taste, Sour (Acidic) {340} [84]

(PW-TPB: 821; 442; 2513; 579; 2111; 340)

  1. If I were to include every single symptom, for the sake of illustration

the translated rubrics would be:

  • Cough, Expectoration, Greenish {618} [34]
  • Aggravation, Situation and Circumstance, Lying, Back, on {2507} [46]
  • Aggravation, Situation and Circumstance, Lying, Head Low, with {2513} [19]
  • Aggravation, Food and Drinks, Greasy (Oily, Fatty) {2355} [39]
  • Sensations and Complaints, Generalities, Pressing (Aching), from Outwards Inwards {821} [63]
  • Taste, Sour (Acidic) {340} [84]
  • Urine, Frothy {458} [5]
  • Urine, Color, Dark {442} [75]
  • Respiration, Hot {579} [17]
  • Fever, Perspiration, Odor, Sour (Acidic) {2111} [28]
  • Sensations and Complaints, Generalities, Burning, Inner parts in {810} [106]
  • Hunger and Thirst, Thirst (Dipsia) {276} [99]

(PW-TPB: 618; 2507; 2513; 2355; 821; 340; 458; 442; 579; 2111; 810; 276)

  1. Sulphur clearly stands out in the chart, followed by Hepar sulphuris calcareum and Nux vomica. Urine frothy (Lachesis muta, Laurocerasus, Lycopodium clavatum, Senega, Spongia tosta) is missing in the top candidates in the ‘everything’ chart. But if I filter to only those 5 remedies in that particular rubric, none of the candidates sound right from our general knowledge of their symptomatology.


  1. Then I remembered my experience of hiking up a volcano in Bali with a group of homeopaths and inhaling the Sulphur vapour. The burning, choking, sour experience clearly resembles the patient’s symptoms. Referring to our primary Materia Media confirms that Sulphur is the best remedy.
  • Hn-CD: in the morning, while dressing, there is again cough, with expectoration, then no more during the day. Coughing up greenish flakes,
  • Hn-MMP: burning up the esophagus, with sour eructation.
  • Hn-MMP: Complete loss of appetite, but constant thirst.
  • Aln-EMMP: the feces were nearly black, loose, viscid, greasy, and had a pungent odor of sulphuretted hydrogen
  • Hn-MMP: Dark brown urine.
  • Hn-CD: Burning in the throat and hot breath in the morning on awaking.- Burning in the chest and intense warmth in the face.
  • Hn-CD: Dry heat in the body, every room is too hot for him. Internal heat with thirst.
  • Hn-MMP : heat in the head and hands, with thirst for beer
  • Hn-CD: sour taste in the mouth; aversion to fat food;
  • Hn-CD: Sour, profuse night-sweat, commencing at once in the evening.
  • Hn-MMP: an occasional painful pressing inwards from the top of the head to deep into the brain, which compels him to wrinkle the forehead and close the eyes.
  • Hn-CD: Pressive headache in the forehead, more violent when moving.- Pressure in the head, from one temple to the other, in the morning after rising.
  1. Prescription: Sulphur 30c (two tiny #10 granules) dissolved in water and take a sip was advised.  This was the only potency available from her friend’s home remedy kit.   She was advised to prepare this medicinal solution once daily for 3 days. She then reported increased expectoration and diarrhoea the next morning, immediately followed by general relief on all levels: sour sweat & breath, hot breath, cough, diarrhoea, urine colour, and overall energy level.

One week update: there remains only minor cough at night, but none during the day, and all other symptoms are gone.  In about ten days, all symptoms  cleared up.


Clemens von Boenninghausen, “Therapeutic Pocket Book (1846)” (Polony & Weaver Translation, 2011), in OpenRep Synopsis Software  (PW-TPB)

Samuel Hahnemann, “Materia Medica Pura”. (Hn-MMP)

Samuel Hahnemann, “Chronic Diseases”. (Hn-CD)

Samuel Hahnemann, “The Organon of Medicine”, 6th Edition.

Timothy Allen, “Encyclopedia of Materia Medica Pura”.


About the author

Arden Wong

Arden Wong is a homeopathic practitioner based in Hong Kong. He graduated from Nature Care College, Sydney, Australia and started full-time practice in 2002. He founded the Hong Kong Academy of Homeopathy in 2014, teaching Hahnemannian homeopathy to lay people and medical professionals in Hong Kong and Taiwan.


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