Hives is listed as a 'see your doctor if...' side-effect of pharmaceutical methamphetamine. Almost any prescription or over-the-counter medication can cause hives. Some of those drugs include antibiotics, pain medications, sedatives, tranquilizers, and diuretics (fluid pills). Diet supplements, antacids, arthritis medication, vitamins, eye and eardrops, laxatives, vaginal douches, or any other non-prescription item can be a potential cause of hives.
Drug-induced urticaria (hives)
Basically hives are usually a result of histamine causing plasma to leak out of small blood vessels in the skin. Histamine is released from 'mast cells' that lie alongside the blood vessels. Usually allergic reactions cause the release of histamine - whether that's from drug reactions, allergies to foods, or sometimes unknown causes. Most episodes of hives only last a few days, and can be relatively easy to pinpoint the source - ie. something new in the diet, clothing or other chemical intake that hasn't been used before. Chronic hives lasting months or years (in recurring bouts) are harder to identify the cause, as sometimes accumulated levels of chemical can cause longer term allergies.
The most common foods that cause hives are nuts, chocolate, fish, tomatoes, eggs, fresh berries, and milk. Fresh foods cause hives more often than cooked foods. Food additives and preservatives may also cause hives.
Hives may appear within minutes or up to two hours after eating, depending on where the food is absorbed in the digestive tract.
I guess the best policy would be to discontinue using meth from that source, whether it was something in that particular meth or not. If you notice something else causing the hives, then you could further investigate. Alternatively talk to your doctor about possibilities of any allergies you have causing hive outbreaks similar to what you experienced.
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