From the Guidelines
For a 15-year-old female with multiple allergic manifestations, I recommend a systematic approach combining detailed history, physical examination, and targeted investigations to reach a definite diagnosis. This approach is based on the guidelines for the diagnosis and management of food allergy in the United States, which emphasize the importance of medical history and physical examination in aiding the diagnosis of food allergy 1.
Key Components of the Approach
- A comprehensive allergy-focused history using a structured questionnaire to document specific triggers, timing of reactions, family history of allergies, and environmental exposures
- A focused physical examination to document all skin lesions, their distribution, and characteristics, paying special attention to signs of atopic dermatitis, urticaria, and angioedema
- Investigations such as skin prick testing for common food allergens and aeroallergens, serum total IgE and specific IgE tests for suspected allergens, and patch testing if contact dermatitis is suspected
Importance of Medical History and Physical Examination
The medical history is useful for identifying food allergens that may be responsible for IgE-mediated allergic reactions, but it lacks sufficient sensitivity and specificity to definitively make a diagnosis of food allergy 1. The physical examination may provide signs consistent with an allergic reaction or disorder often associated with food allergy, but by itself, it cannot be considered diagnostic of food allergy 1.
Investigations and Diagnostic Tests
The investigations should include skin prick testing, serum total IgE and specific IgE tests, and patch testing if necessary. An elimination diet followed by controlled food challenges under supervision may help identify triggers for gastrointestinal symptoms. Complete blood count, ESR/CRP, and tryptase levels during acute episodes can help differentiate allergic reactions from other conditions.
Referral Guidelines
Referral to an allergist-immunologist may be necessary to confirm the diagnosis of atopic dermatitis, identify the role of dust mite allergy or food allergy in patients with atopic dermatitis, and manage patients whose atopic dermatitis responds poorly to treatment 1.
Systematic Approach
This systematic approach helps distinguish between true IgE-mediated allergies, non-IgE-mediated reactions, and other conditions that may mimic allergic symptoms, allowing for targeted management of this complex presentation. It is essential to follow a step-by-step approach to reach a definite diagnosis and provide appropriate treatment for the patient.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Approach to Diagnosis
To reach a definite diagnosis for the 15-year-old female patient with a history of food allergy, swelling of lips and tongue, angioedema, itching, urticarial disease skin lesions, abdominal pain, distention, skin erosions, itching all over the body, atopic dermatitis, conjunctivitis, and a confusing patient history, the following steps can be taken:
- Take a directed history to identify potential allergens and correlate them with the patient's symptoms 2, 3
- Perform a physical examination to look for signs of allergic reactions, such as wheals, angioedema, and skin lesions 2, 4
- Use skin testing, such as prick or patch testing, to identify specific allergens and confirm the diagnosis of allergy 2, 3, 4
- Consider in vitro tests, such as serum IgE tests, to measure specific IgE levels and confirm the diagnosis 4
Diagnostic Tests
The following diagnostic tests can be used to aid in the diagnosis:
- Skin prick test (SPT) to identify sensitivity to inhalants, foods, and other allergens 4
- Patch testing to identify type IV hypersensitivity reactions 3
- Serum IgE tests to measure specific IgE levels and confirm the diagnosis 4
- Ulcer biopsy for microbiologic, DIF, and histopathologic evaluation to rule out atypical ulcers 5
Considerations
When interpreting the results of diagnostic tests, consider the following:
- Correlate skin testing results with the presence of clinical symptoms to confirm the diagnosis of allergy 2
- Consider the relevance of sensitivity to allergens in the light of the clinical history, as sensitization and clinical allergy may not coincide 4
- Be aware of the potential for systemic reactions, including anaphylaxis, and take necessary precautions when performing skin testing 4