The Four-Day-Rule-Of-Thumb: this is a diagnostic tool I used to help uncover the root cause of people's hives (a form of allergy).

Often times a customer will come in with a skin rash all over their body and ask for an antihistamine. Of course I give them what they want but when I notice they're not in a hurry I'll ask to give them my 2cents.

Recognising that hives is a whole body reaction oftentimes to stress-overwhelm, and NOT to the last meal they had, I'll usually proceed with a four day survey of what they have been up to: any recent illness? recent overseas travel? (unlikely during COVID-19), recent diarrhoea? recent sports carnival or school camp? recent excursion? What I'm looking for a signals of stress in all its forms:

-stressed immune system (illness)

-poor sleep (jet lag)

-dehyration (diarrhoea, excess caffeine, not enough water)

-physical exhaution (sports, gym, outings in the sun

Note I might query what their dietary choices are like, but often I find this a little intrusive and people get self-conscious so I might even skip it and glean from the aforementioned questions how their immunity status is looking.

What I'll often see is a pattern of of compounding stresses, day after day, and so by the fourth or fifth day, it's just too much, the immunity is at critical threshold, any further stress will set off the whole body into hives. Any guess for what that last thing is? Yep, its usually their last meal.

Hang on you say, "How come you said earlier that the meal isn't the culprit and now I say it is?" Let me explain: the meal is the final straw that broke the camel's back. On it's own any other time of the month it's not a trigger. But with multiple stresses e.g. A (jet lag) + B (dehyration) + C (exhaustion) + D (last meal) = hives!

So stepping back, simply understand that the body can only take so much in a four day period before it'll stress out. Often times I see hives on a Sunday or Monday because of the weekend's activities.

I hope that helps!

If you have any general questions, leave em below.

Leave specific questions to your doctor =)

xoxo Smiling Pharmacist