Allergies: Symptoms, Causes, and Diagnosis

This post was written with Consensus AI Academic Search Engine – please read our Disclaimer at the end of this article. Allergies present a wide range of symptoms and are caused by various allergens, with food and inhaled substances being the most common. Accurate diagnosis requires a combination of clinical history, skin and blood tests, and food challenges. Understanding the specific allergen and the individual’s response is crucial for effective management and treatment of allergies.

Symptoms of Allergies

Allergies manifest through a variety of symptoms depending on the allergen and the individual’s sensitivity. Common symptoms include atopic dermatitis, acute urticaria, gastrointestinal reactions, and systemic anaphylaxis2. Respiratory symptoms such as wheezing and asthma can also be triggered by food allergies, although this is less common2. In cases of allergic rhinitis, symptoms include nasal congestion, sneezing, and itching, often triggered by pollen or dust mites9.

Causes of Allergies

Allergies are caused by an overreaction of the immune system to typically harmless substances known as allergens. These allergens can be ingested, inhaled, or come into contact with the skin. Common food allergens include cow’s milk, hen’s egg, wheat, soya, citrus fruits, fish/shellfish, nuts, and chocolate1. Inhaled allergens such as pollen, dust mites, and animal dander are also significant triggers7. Genetic predisposition and environmental factors play crucial roles in the development of allergies8.

Diagnosis of Allergies

Diagnosing allergies involves a combination of clinical history, skin tests, blood tests, and food challenges. A detailed clinical history is essential to identify suspected allergens and the temporal association of symptoms3. Skin prick tests (SPTs) and serum-specific IgE tests are commonly used to detect sensitization to specific allergens5 7. However, these tests have limitations in specificity and predictive values, making them insufficient for a definitive diagnosis on their own4 5.

The gold standard for diagnosing food allergies is the double-blind, placebo-controlled food challenge (DBPCFC), which provides the most accurate results1 3 4 5. This method involves administering the suspected allergen and a placebo in a controlled setting to observe any allergic reactions. For respiratory allergies, nasal smear for eosinophils (NSE) can be a valuable diagnostic tool, especially in cases where skin tests are negative9.

Disclaimer

The content presented in this blog is generated by Consensus, an AI-powered academic search engine, and is based on publicly available scientific literature. While every effort is made to provide accurate, up-to-date, and well-researched information, the content is intended for informational and educational purposes only. It does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional before making any decisions regarding medical conditions, treatments, or medications. The AI system’s analysis may not cover all perspectives, emerging research, or individual cases, and it is not a substitute for professional expertise. Neither the blog publisher nor the developers of the AI-powered search engine are responsible for any actions taken based on the information provided in this content. Use of this information is at your own risk. Citations to the original scientific studies are included for reference, but these studies should be reviewed in full and interpreted with the guidance of a healthcare or research professional.

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