It’s a shock in the fight against anaphylaxis.

Affecting 1 in 13 children in the US, food allergies saw a 50% increase between 1997 and 2011 — a jump due to several factors, including more refined diets, vitamin D deficiencies and the “hygiene hypothesis,” which posits cleaner environments cause the immune system to overreact to certain foods.

But parents can slash their baby’s risk of one of the most common food allergies in one easy step, according to a new study.

Some of the most common food allergies for infants include wheat, fish, dairy, nuts (especially peanuts), soy and egg.

The general recommendation is to wait until your baby is at least 6 months old to feed them eggs, with guidelines from the early 2000s recommending avoiding it until they’re 1 to 3 years of age.

However, a study published Monday in JAMA Pediatrics is recommending earlier introductions to reduce food allergies.

Comparing two Australian population samples of 1-year-old infants, the study found that earlier egg intake resulted in a decrease of egg allergy prevalence from just over 9% of the participants to only 7.6%.

As for why serving your kiddo up some scrambled eggs could reduce their chances of an allergic reaction, health experts believe it has to do with how the allergen is introduced.

“What we know about the immune system is that if an allergen is introduced initially through skin exposure, the body actually produces an allergic response,” Dr. Gina Coscia, an attending physician of the Division of Allergy and Immunology at Northwell Health who was not involved with the study, told The Post.

“However, if the initial introduction of a food allergen is through oral exposure, through ingestion of the food, that actually produces a protective response to the allergen,” Coscia added.

The new recommendations are a major change from current guidelines, which say to avoid allergenic foods until three years at the latest — particularly in kids with a family history of allergies.

Coscia also notes that one of the most important takeaways from the study was the effects on children with eczema.

An inflammatory condition characterized by dry, red and intensely itchy skin, eczema makes sufferers particularly vulnerable to food allergies because of the impaired skin barrier.

“Seeing concrete evidence that this reduction in the prevalence of food allergy is even more pronounced in babies with eczema is so important because we have a specific group of patients that we can educate even more emphatically about the importance of early introduction,” Coscia explained.

Previous research has shown that introducing peanuts earlier actually resulted in a 77% decrease in peanut allergies for 4-month-old infants with severe eczema and 6 months for those with mild or no eczema.

And while food allergies are often genetic, a baby’s diet and when they start eating certain foods can also have an impact on whether allergies develop.

Another study found that 9-month-old babies eating a diverse diet consisting of 13 or 14 different foods was associated with a 45% decrease in the risk of food allergies by the time the infant reached 18 months.

Beyond introduction at an earlier age, Coscia also recommends another crucial step to avoid potential food allergies.

“Maintenance of this allergen several times a week is critical in order to remain tolerant to the food,” she said.