HIVES: Always a real emergency…or not?
Other than a true cardiac or respiratory arrest, there are few situations in my business where I interrupt anything and everything to go examine a patient at the door. Here’s a short list:
- current seizure activity
- broken bone with deformity
- anaphylaxis/allergic reaction
- uncontrolled bleeding
There may be a couple more, but as you see the list is fairly short. I’m not saying that other clinical scenarios aren’t actual emergencies, but most of the time I don’t need to stop caring for my current patient before moving on to care for my next patient.
So recently I’ve seen more than three children who have come to be evaluated for hives.
HIVES! We usually think of that as part of anaphylaxis, which is on the list above, so clearly this gets my attention at the doorway. After running to see these guys, I come to find out that they all have had hives for days. DAYS. Itchy, red, raised bumps scientifically known as urticaria all over their bodies. If you haven’t seen them, they look a bit like mosquito bites.
After taking a very large breath I realize that the parents of these children have the same fear that I did initially- that their child was having an acute allergic reaction. They did the right thing by seeking medical care, but after understanding the whole clinical picture I realized that the diagnosis wasn’t an allergic reaction at all, which was a big surprise to these moms and dads. See, here’s the thing- in the majority of cases, hives in children (especially those that last for days) are often caused by a viral infection and not an allergy at all. It’s estimated that around 80% of all hives in children are caused by a virus.
Awesome, right— another thing we can blame on viruses. Let’s get into it a bit and understand how this situation differs from the hives that happen in the setting of an allergic reaction.
FIRST, HOW ARE THEY THE SAME?
- Hives are hives, and look alike regardless of cause. The skin gets a signal to fire up an inflammatory response, and it appears not to care why. The default skin manifestation is hives.
- They can appear in a very short amount of time from both causes. Sometimes even over minutes. And they can come and go over several hours.
- Hives in the setting of either situation can be itchy. Or not.
OK, THEN HOW ARE THEY DIFFERENT?
- Most of the time, hives due to an acute allergic reaction fade relatively quickly with medicines like diphenhydramine (Benadryl and similar) and other anti-histamines. Viral induced hives are often not as responsive.
- Hives due to an acute allergic reaction usually do not reappear days later after treatment. Viral induced hives can.
- Viral induced hives are often associated with other symptoms like fever, cough, and even vomiting and diarrhea.
- Hives due to anaphylaxis need medication (often many) and ongoing management, often including carrying an epi-pen at all times. Viral induced hives just need time and patience; rarely any medicine.
- Viral-induced hives often appear after a patient has been on antibiotics for multiple days, and hives from a true drug allergy occur right after the exposure.
Sometimes, in the thick of it all, it’s can be hard to tell if the source of the hives is due to an allergy to something or if it’s simply from a virus. I always encourage anyone with hives to get checked out regardless: the devil is often in the details and the situation requires a skilled and experienced healthcare provider to figure it out.
If you or your child has hives and any of the following:
- Difficulty breathing
- Lip swelling
- Hoarse voice
…then 911 should be called and/or immediate care needs to be sought. This is a life-threatening situation.
It’s sort of weird that viral induced hives account for such a high percentage of hives in children, yet in my experience so few people are aware of its existence. Hopefully the time spent reading this blog entry changes that a little. Now YOU know!