Pediatric Allergy and Immunology

These conditions are often or exclusively caused by allergic reactions, with symptoms that primarily affect a child’s nose, sinuses, eyes, face, and ability to breathe comfortably.

Allergic conjunctivitis

Conjunctivitis (pink eye) caused by allergens rather than germs. Symptoms include reddish eyes that are itchy, burning, puffy, or watery.

Allergic rhinitis (hay fever)

Congestion, sneezing, coughing, and other cold-like symptoms caused by breathing in allergens such as pollen, pet dander, dust mites, or mold spores. Hay fever can occur any time of year, but symptoms are often seasonal (based on when your child’s specific triggering allergens are more likely to be in the atmosphere).

Asthma

This condition can trigger narrowing of the airways (the tubes that carry oxygen to the lungs), which can lead to episodes of breathing difficulty, including coughing, wheezing, chest tightness, and shortness of breath.

Chronic rhinosinusitis (chronic sinusitis)

Symptoms of this condition include runny nose, congestion, difficulty breathing, and facial swelling or tenderness that lasts 12 weeks or more, due to chronic swelling of sinuses in the nose and face.

Nasal polyps

Small, non-cancerous growths that form in the nose or sinuses, often as a result of chronic asthma or other respiratory allergies. Polyps may block nasal passages and make it more difficult to breathe.

These allergic conditions affect the digestive tract, including the esophagus, stomach, and intestines. They include:

Eosinophilic esophagitis

Excess amounts of specific white blood cells called eosinophils collect in the esophagus (the tube that connects the mouth and stomach), which can lead to difficulty swallowing, heartburn, and chest pain.

Food protein-induced enterocolitis syndrome (FPIES)

Certain foods trigger symptoms similar to severe gastroenteritis (stomach flu) within a few hours of eating them. These symptoms can include vomiting, diarrhea, pain, and chills.

These complex conditions include disorders that weaken the immune system (immunodeficiency) or cause it to react in unexpected, harmful ways (immune dysregulation). Most are genetic and present at birth (inborn errors of immunity, also known as primary immunodeficiencies). However, immunodeficiency can also be caused by external factors like infections, medications, or cancer. Specific conditions include:

Adenosine deaminase (ADA) deficiency

Due to a genetic condition, the body cannot produce enough (or any) of an enzyme called adenosine deaminase (ADA). This starts a chain reaction in the body making it hard to produce healthy white blood cells and fight off infections. ADA deficiency is a common underlying cause of moderate-to-severe immunodeficiency disorders.

Hypereosinophilic syndrome

Highly elevated levels of eosinophils (a type of white blood cell) in the bloodstream cause chronic inflammation throughout the body and damage organs over time. Symptoms depend on what organs are affected, but may include skin rashes, cough, fatigue, belly pain, chest pain, or nausea.

Hypogammaglobulinemia

The body doesn’t produce enough (or destroys too many) antibodies, proteins that are critical for fighting infections. Children with this condition tend to get more frequent infections that cause longer periods of sickness.

Severe combined immunodeficiency (SCID)

This disorder occurs when the body is completely unable to produce working copies of critical white blood cells. This results in the immune system being entirely unable to function. Without treatment, even mild illnesses can be life-threatening for children with this disorder.

These conditions are frequently caused by allergic reactions, with symptoms that primarily affect the skin. They include:

Angioedema

Fluid leaking from blood vessels in the lower layers of skin can cause swelling, especially (but not exclusively) in the lips, eyelids, hands, and tongue. Angioedema that occurs in the airways can cause breathing difficulty. Children are sometimes born with the condition (hereditary angioedema), but it can also be triggered by allergies, reactions to certain drugs, or repetitive vibrations.

Atopic dermatitis (eczema)

Dry, itchy skin rashes that may hurt or ooze. They happen when the skin has trouble holding in moisture and keeping out irritants and germs.

Contact dermatitis

Direct skin contact with an allergen or irritant (such as harsh soaps, perfumes, or poison ivy) can cause dry, itchy, cracked, or scaly and painful rashes.

Hives (urticaria)

Raised, itchy bumps on skin that often appear reddish or pinkish on people with lighter skin, but not discolored (or only slightly lighter or darker) on people with darker skin.

Mast cell disorders

These conditions occur when mast cells, which act as an early warning system and first line of defense against infection, trigger excessive or unnecessary immune responses. Symptoms often include skin flushing, rashes, or sores. They may also include digestive problems, joint pain, or headaches. Specific conditions include mastocytosis (elevated levels of mast cells in the body) and mast cell activation syndrome (hypersensitive mast cells).

Systemic allergic reactions affect multiple parts of the body, such as the skin, respiratory system, and gastrointestinal tract.

Severe systemic reactions can lead to anaphylaxis, a severe and rapidly progressing allergic reaction that can be fatal if not recognized and treated immediately. Early signs may include skin rashes, swelling, difficulty breathing, and dizziness.

If your child is experiencing symptoms of anaphylaxis, immediately give them epinephrine (if available; this is usually administered via an epi pen) and call 911. Without emergency treatment, anaphylaxis progresses to loss of consciousness, inability to breathe, lack of blood flow to vital organs, and possibly death. Allergies most likely to cause systemic reactions and anaphylaxis in children include:

Drug allergies

While most drugs have side effects, some people experience excessive allergic reactions to certain medications. Most drug allergies cause mild rashes or cold-like symptoms, but severe cases can cause anaphylaxis.

Food allergies

Allergic reactions that develop within minutes to a few hours of eating certain foods, such as milk, peanuts, shellfish, soy, or wheat. Symptoms can be severe or life-threatening for some individuals, even if previous reactions were less severe. Food allergies are the most common trigger for anaphylaxis in children.

Insect sting allergies

Stings from insects including bees, wasps, and ants can cause allergic reactions in some people. Milder reactions may cause swelling, pain, welts, or rashes near the site of the sting. Severe reactions can cause anaphylaxis.