Son #2 did not sleep well last night- lots of whining and refusing to sleep anywhere but my lap... :(
I initially couldn't figure out what the problem was, but it became clear when I switched on the light during a diaper change- little munchkin was covered in an itchy red bumpy rash! He's had eczema and hives before, but it resolved completely with the elimination of strawberries from my diet almost 3 months ago (I'm still nursing, and he is allergic).
This morning, after giving him a bath, lubing him up with hydrocortisone and petroleum jelly, and forcing some Zyrtec into his mouth, the detective work began. Hopefully, writing down my process here will help you understand how your allergist determines which exposures are most likely to be triggering allergic symptoms in you or your kids.
Rash is generalized (on face and body)- so it could be either something ingested (food sensitivity) or something applied to the skin topically (lotion, detergent, etc...)
Let's start with topical exposures, because they're easier to pinpoint:
Cleanser- Johnson Baby Wash- been using it since birth without problems, unlikely to be the culprit
Moisturizer- Burt's Bees for Sensitive Skin- been using it since birth without problems, unlikely to be the culprit
Laundry- All Free Clear liquid, no fabric softener, hot water, extra rinse cycle- can't get much more hypoallergenic than that!
OK- topicals cleared. Moving on to systemic exposures...
48 hours ago- immunizations! But baby tolerated the same vaccinations beautifully twice in the past. Besides, allergic reactions to vaccines generally present as immediate urticaria (hives) rather than delayed skin reactions.
Now comes the hard part- food diary! No new foods for baby this week, so let's document everything mommy has consumed over the past 72 hours. Although baby's rash appears partly eczematous (a reaction that generally occurs 48-72 hrs after exposure), it also has elements of an urticarial eruption (hives that usually occur with 4 hours of exposure). So, the culprit could be anything consumed in the 72 hour time frame. Also, we should keep in mind that food proteins generally take around 4 hours after ingestion to show up in breastmilk.
Skipped breakfast (bad mommy!)
Lunch: cream of broccoli soup, grilled chicken salad, a pear, half a can of Pepsi
Snack: 2 bites of a strawberry Nutrigrain bar before I realized it was strawberry (oops!)
Dinner: Portillo's hot dog, breadsticks with marinara sauce
Breakfast: Cheerios and milk, potato paratha (yum!), plain yogurt
Lunch: 1/2 cheeseburger, orange juice
Dinner: lentil stew and rice
Breakfast: Cheerios and milk, cumin cookie, orange juice
Lunch: Ground beef and vegeatbles, Italian bread, orange juice
Dinner: Lamb stew with potato, rice, yogurt, orange juice
None of these foods are new to me or my itchy little bundle of joy, but as you can see highlighted above, I seemed to have quite a craving for OJ over the last 48 hours!
Oranges and other citrus fruits have the ability to induce histamine release from mast cells (white blood cells) in the skin when consumed in sufficient quantities, even if you're not truly allergic. This is known as non-specific mast cell degranulation.
Although I have been able to drink the occasional glass of orange juice or eat a clementine here and there, it appears the my recent orange juice binge has exceeded baby's threshhold. The timeline fits too- I loaded up with OJ all day, but kiddo didn't get exposed until late evening when I returned hom from work. Rash developed overnight and improved markedly after the interventions listed above. This means that it was predominantly immediate in nature, and that I need to watch my intake of citrus. I'll abstain completely for a couple of weeks, and then slowly reintroduce it in small amounts until I determine how much son #2 can tolerate.
In addition, once the Zyrtec leaves his system (at least 5 days), I'll probably skin test him to orange. If it's negative (which is pretty accurate at predicting that it's not allergy) and baby has tolerated reintroduction, my focus on citrus may have been misplaced. But for now, I think it's the most plausible explanation.
Hope this peek into the allergist's thought process has been helpful!