WHEN patients come to doctors with acute (recent) or chronic (long-term) respiratory symptoms, in just the same way they should be asked whether there is any cigarette smoke within the house, they should likewise be asked whether there might be ganja (marijuana) smoke in the house.

Tiny particulate substances may be suspended within the smoke, and also embedded within clothing and on furniture, and the like, within the home.

Allergy to ganja has often been reported in adults who use it, but the first report of a young child with a positive allergy test to marijuana was presented recently at the 2018 Annual Scientific Meeting of the American College of Allergy, Asthma & Immunology. The six-year old boy had been exposed only to second-hand smoke from ganja being used inside the house.

The situation came to light as the young boy had severe asthma and nothing was making him better. He had daily symptoms of coughing, shortness of breath and wheezing.

Careful questioning with open-endedness and frankness subsequently revealed that some family members had recently started smoking marijuana in the house.

Second-hand smoke

Although family members said they were not using the substance in the same room as the child, the child’s grandmother reported she had broken out in a full-body skin allergic reaction in the past when she had used marijuana. So the doctor attending to the child requested testing for allergy to marijuana, as this would suggest that genetic make-up was playing a part in the process.

To test for this, researchers added saline to the same kind of marijuana the family had been using to create a puddle sample, and then pricked the skin of the child with it. They also pricked the skin of his grandmother and a third person as well who acted as a negative control subject (a neutral person used as a contrast to gauge any response).

At the end of the test, the diameter of the wheal in the skin of the boy was 9x8mm, and that of his grandmother 15x8mm. The control subject tested negative. To rule out coincidences, additional tests were also conducted on the three individuals, using peach and tomatoes (which were shown in the research literature to have a cross reaction to marijuana) and making comparisons. One set of white blood cells that are activated in allergic reactions are basophils, and so a basophil activation test of marijuana as well as for peach and tomato were performed.

The results

The results showed that the young boy demonstrated basophil activation to marijuana with very pronounced differences when compared to that of the controlled person at 1:20 and 1:100 dilutions. As the peach and tomato tests were negative, this presented strong evidence that the patient was allergic to marijuana, the researchers informed.

To provide even more proof, the research team advised the family to rid the house of any marijuana in order to further test the findings three months later, and by then, the child’s symptoms were all improved. His respiratory airways were tested to confirm this. Before the removal of the substance, the asthma-control questionnaire provided a score of 25 — well above acceptable levels.

Three months after the marijuana smoke was eliminated from the house, the score had dropped to 19, showing significant improvement for peripheral airways disease. The child had got better both subjectively and objectively.

The lobby

So as the lobby increases for more US states and countries of the Caribbean to legalise marijuana for medical and recreational use, doctors must pursue a particular line of questioning when attending to patients with respiratory symptoms, including asking about ganja use in and around the home. This is even more important when treating young patients.

As science and technology develops, more effective ways will also need to be found to separate and test the several active ingredients present in ganja (marijuana). It has been a well-known fact that ganja smoke is an irritant to the airways (bronchi and lungs), producing persistent coughing, chronic bronchitis, and other respiratory symptoms and signs, but with these research findings we now know that people are also allergic to it. Please spread the word so that all can be on the look-out.

Dr Derrick Aarons MD, PhD, is a family physician and consultant bioethicist; a specialist in ethical issues in health care, research, and the life sciences; the health registrar and head of the health secretariat for the Turks and Caicos Islands, and a member of UNESCO’s International Bioethics Committee (IBC).