Allergy and Immunology — Find Specialists & Top Hospitals Worldwide | MyMedicPlus

Allergy and Immunology is a combined medical specialty focused on the diagnosis, treatment, and long-term management of allergic diseases and disorders of the immune system. Allergist-immunologists are uniquely trained to manage both the exaggerated immune responses that cause allergies and the deficient or dysregulated immune responses that lead to immunodeficiency diseases.

The specialty bridges several organ systems — respiratory, skin, gastrointestinal, and systemic — because allergic reactions can affect any part of the body. Unlike a pulmonologist who focuses only on asthma from a lung perspective, or a dermatologist who may treat eczema from a skin perspective, an allergist addresses the underlying immune mechanism driving these conditions across the entire body.

Subspecialties within allergy and immunology include clinical immunology (primary immunodeficiency disorders), pediatric allergy (managing allergic disease from birth through adolescence), occupational allergy (workplace exposures), and drug allergy evaluation. Many allergists also manage complex or difficult-to-control asthma, recurrent angioedema, and mast cell activation disorders. The field has grown rapidly with the introduction of biologic therapies that target specific immune pathways, dramatically improving outcomes for patients with severe allergic disease.

Allergist-immunologists diagnose and manage a wide spectrum of immune-related conditions:

• Allergic rhinitis (hay fever): Seasonal or year-round nasal inflammation caused by inhaled allergens such as pollen, dust mites, and pet dander, leading to sneezing, nasal congestion, and itchy eyes.
• Asthma: Chronic airway inflammation causing reversible bronchoconstriction, wheezing, shortness of breath, and coughing; allergic asthma is the most common type.
• Food allergies: Immune-mediated reactions to foods such as peanuts, tree nuts, shellfish, milk, eggs, and wheat, ranging from hives to life-threatening anaphylaxis.
• Drug allergies: Adverse immune reactions to medications including penicillin, sulfonamides, NSAIDs, and contrast agents.
• Insect sting allergy: Systemic allergic reactions to bee, wasp, and fire ant venom that may cause anaphylaxis.
• Atopic dermatitis (eczema): Chronic, relapsing inflammatory skin disease strongly associated with allergic sensitisation and immune dysregulation.
• Urticaria and angioedema: Recurrent hives and deep tissue swelling with or without an identifiable allergic trigger.
• Anaphylaxis: Severe, potentially life-threatening systemic allergic reaction requiring emergency epinephrine treatment.
• Primary immunodeficiency disorders: Inherited conditions causing recurrent infections, such as common variable immunodeficiency (CVID) and IgA deficiency.
• Allergic contact dermatitis: Delayed immune reactions to chemicals, metals, or other contact allergens identified by patch testing.
• Eosinophilic disorders: Conditions including eosinophilic esophagitis and eosinophilic asthma driven by elevated eosinophil counts.

Allergist-immunologists use a range of diagnostic tests and therapeutic interventions specific to their specialty:

• Skin prick testing: The gold standard for identifying environmental and food allergen sensitivities. Small amounts of allergen extracts are placed on the skin and a lancet creates a superficial scratch; a wheal-and-flare reaction indicates sensitisation.
• Intradermal allergy testing: More sensitive than skin prick testing, used when skin prick results are negative but clinical suspicion remains high, particularly for drug and venom allergies.
• Specific IgE blood testing (ImmunoCAP/RAST): Measures allergen-specific IgE antibodies in blood when skin testing is not possible due to severe eczema, dermographism, or antihistamine use.
• Oral food challenges: Supervised, graded feeding of a suspected food allergen to confirm or rule out a food allergy diagnosis; performed only in a medically equipped setting.
• Pulmonary function testing (spirometry): Measures airflow obstruction and bronchodilator reversibility to diagnose and monitor asthma severity.
• Methacholine challenge test: Confirms bronchial hyperresponsiveness in patients with suspected asthma but normal baseline spirometry.
• Allergen immunotherapy (allergy shots): Subcutaneous injections of increasing allergen doses to desensitise the immune system over 3–5 years, reducing allergy symptoms and preventing asthma progression.
• Sublingual immunotherapy (SLIT): Daily allergen drops or tablets placed under the tongue; an alternative to injections approved for certain grass, ragweed, and dust mite allergies.

Referral to an allergist-immunologist is appropriate in several clinical situations where immune-mediated mechanisms are suspected or confirmed:

Seek evaluation if you experience recurrent or unexplained anaphylaxis, especially without a known trigger — an allergist can identify the cause and provide emergency action plans with epinephrine auto-injectors. Patients with asthma that is not controlled despite inhaled corticosteroids and long-acting bronchodilators benefit from specialist assessment to identify triggers, adjust therapy, or initiate biologics such as dupilumab or mepolizumab.

See an allergist if you have a suspected food allergy causing systemic reactions — confirmation by supervised oral food challenge is essential before lifelong dietary restriction. Patients with recurrent hives or angioedema lasting more than 6 weeks (chronic urticaria) or with hereditary angioedema deserve specialist evaluation. Adults or children with frequent sinopulmonary infections (more than 4 bacterial infections per year), failure to thrive, or opportunistic infections may have a primary immunodeficiency requiring immunoglobulin replacement therapy. Anyone with a history of penicillin allergy that has never been formally evaluated may benefit from drug allergy testing, as up to 90% of such patients are not truly allergic.

Becoming a board-certified allergist-immunologist requires an extensive training pathway. The journey begins with a 4-year medical degree (MD or DO), followed by completion of either an internal medicine residency (3 years) or a pediatrics residency (3 years), both of which provide the clinical foundation for managing complex patients across age groups.

Following residency, candidates undertake a 2-year fellowship in Allergy and Immunology, during which they train in adult and pediatric allergic diseases, clinical immunology, rhinology, pulmonology, and dermatology as they relate to immune-mediated conditions. Fellows gain supervised experience in skin testing, immunotherapy administration, challenge protocols, and immunoglobulin therapy.

Board certification is granted by the American Board of Allergy and Immunology (ABAI), a conjoint board of the American Board of Internal Medicine (ABIM) and the American Board of Pediatrics (ABP). Candidates must pass a rigorous written examination. Certification requires ongoing continuing medical education and periodic recertification to maintain current competency. In the UK, the equivalent training leads to Fellowship of the Royal College of Physicians (FRCP) with a subspecialty endorsement in immunology.

Your primary care physician or pediatrician can provide a referral to a board-certified allergist-immunologist. When searching independently, verify board certification through the American Board of Allergy and Immunology (ABAI) directory or your country's equivalent medical regulatory body.

For your first appointment, bring a detailed symptom diary documenting when reactions occur, what you were exposed to, how long symptoms last, and what treatments helped. List all current medications, including over-the-counter antihistamines (which must usually be stopped 5–7 days before skin testing). Expect an in-depth medical history, a physical examination, and likely allergy skin testing during the initial visit. For patients with suspected immunodeficiency, blood tests including immunoglobulin levels and lymphocyte subsets will be ordered. Treatment plans are individualised and may include avoidance strategies, pharmacotherapy, or long-term immunotherapy.