Measles, mumps, and whooping cough outbreaks have been reported in the United States in recent months.  In other countries, children have become ill with the measles and polio.  All these diseases, once common to childhood, can be avoided by a full regimen of vaccination but more and more parents are choosing to forego immunizing their children.  One reason sometimes cited for opting out of immunization is a child’s history of allergies to previously given vaccines.  A new report from the Johns Hopkins Children’s Center, however, says vaccine allergies are no reason to shun childhood inoculation.

Instead, the research team, led by Robert Wood, MD, chief of pediatric Allergy and Immunology at the children’s center, says he and his team of colleagues have devised a guide pediatricians can use to quickly and effectively identify children most likely to suffer an allergic reaction to a vaccine and it even offers ways to immunize even the most allergic of children.

Allergic reactions can be life threatening and children who’ve suffered a  reaction to a previous vaccine are at increased risk of doing so again.  The first such reaction can be serious but those that come later are usually even more dangerous.  Only one or two vaccinations per million result in a true allergic reaction and immediate medical attention is required.  These are the issues addressed in the Hopkins guide, according to the September issue of the medical journal, Pediatrics.

Many of the vaccines given today are formulated from a gelatin or egg protein base, which is often the allergen causing the reaction.  When parents and pediatricians are aware of a child’s history of allergies to these substances, vaccine formulations free of these allergens can be used instead.

When there is no history of known allergic reactions to vaccines but precautions are still advised, parents can have an allergist administer standard allergy tests, including the skin prick test, to determine in advance if special measures are needed.

Even when an allergic reaction occurred in a child’s past, he or she may have developed enough antibody to the targeted disease that further vaccinations can possibly be delayed or avoided.  The Johns Hopkins team says an allergic reaction to one particular vaccine doesn’t necessarily mean a child will be allergic to all vaccines.  Antiallergy medications, such as corticosteroids and antihistamines, begun a few days before vaccination can often minimize allergic response.

Allergic reactions occur quickly after exposure to an allergen, in this case the vaccine.  Symptoms include wheezing, coughing, hives, swelling, low blood pressure, diarrhea, and vomiting.  A life-threatening condition, anaphylaxis, can occur.  Regardless of symptoms, getting prompt medical attention is vital.

For this reason, the Johns Hopkins research team suggests any child with a history of vaccine allergies should get immunized only at clinics or other medical facilities that are equipped to treat patients suffering from anaphylaxis and other severe allergic reactions.  Several hours may elapse before allergic reaction begins so parents are urged to keep their allergic children under medical observation for several hours after vaccination for the safest outcome.

The Centers for Disease Control and Prevention funded the study.

Source: Johns Hopkins Medical Institutions