co-trimoxazole allergy

Co-trimoxazole, an antibiotic medication, can induce various skin reactions, primarily of allergic origin. These reactions can range from mild to severe and are characterized by:

• Skin rashes and itching [7]
• Fever with or without a skin rash [8]
• Mild to severe blistering rash [9]

In some cases, co-trimoxazole allergy can lead to more serious conditions, such as:

• Drug reaction with eosinophilia and systemic symptoms (DRESS) [2], which involves fever, skin rash, and abnormalities in blood counts
• Stevens-Johnson syndrome (SJS), a life-threatening condition marked by skin rash, ulcers in the mouth/throat/nose/genitals, fever, and potential progression to more severe complications [4][5]

It's essential to note that co-trimoxazole allergy can occur in approximately 1% of patients prescribed this medication, with symptoms such as rash occurring in >1 in 100 patients [6]. If a rash or other allergic symptoms appear, it is crucial to discontinue the medication immediately and seek medical attention.

References: [1] Co-trimoxazole can induce a large number of different skin reactions, mainly of allergic pathogenesis. [2] Drug reaction with eosinophilia and systemic symptoms (an allergic type reaction in which you may develop fever, skin rash, and abnormalities in blood and ... [3] The most common side effects were gastrointestinal disturbances (nausea, vomiting, anorexia) and allergic skin reactions (eg, rash, urticaria). [4] These are life threatening skin-reactions, that are characterized by skin rash, multiple ulcers in the mouth/throat/nose/genitals, fever, and may progress to ... [5] Skin reactions such as SJS may cause severe rash, crusting or ulcers of the mouth or genitals, burning skin and large layers of skin to flake off. [6] With co-trimoxazole a rash occurs in >1 in 100 patients prescribed it. If a rash occurs, discontinue co-trimoxazole immediately. [7] Signs of a mild allergic reaction include skin rashes and itching, high temperature, shivering, redness of the face, a feeling of dizziness or headache. [8] The allergy is characterized by symptoms such as fever with or without a skin rash and itchiness. If this occurs, call your doctor immediately. [9] Sulfonamide antibiotics can cause allergic reactions that range from a mild to severe blistering rash, and can cause severe allergic reactions (anaphylaxis).

Common Signs and Symptoms of Co-trimoxazole Allergy

Co-trimoxazole, a combination antibiotic containing sulfamethoxazole and trimethoprim, can cause allergic reactions in some individuals. The symptoms of an allergy to co-trimoxazole can range from mild to severe.

• Mild Allergic Reactions: These may include:
  • Skin rashes or hives [2]
  • Itching or redness of the skin [3]
  • High temperature (fever) [2]
  • Shivering or feeling cold [2]
  • Redness of the face [2]
  • Dizziness or a feeling of faintness [5]
• Severe Allergic Reactions: These can be life-threatening and require immediate medical attention. Symptoms may include:
  • Swelling in the face, lips, tongue, or throat [7]
  • Breathing difficulties [7]
  • Fainting [7]
  • A severe rash [7]

In addition to these symptoms, individuals with a sulfa allergy (which includes an allergy to co-trimoxazole) may experience: * Skin Reactions: Rashes, hives, or itchy skin upon contact with the medication [8] * Gastrointestinal Disturbances: Nausea, vomiting, diarrhea, loss of appetite, and feeling sick [6]

If you suspect an allergic reaction to co-trimoxazole, seek medical help immediately. Inform your doctor about any previous allergies or sensitivities.

References: [1] Not applicable (initial query) [2] Context 1 [3] Context 3 [4] Context 4 [5] Context 5 [6] Context 6 [7] Context 7 [8] Context 8

Diagnostic Tests for Co-trimoxazole Allergy

Co-trimoxazole, a combination antibiotic consisting of sulfamethoxazole and trimethoprim, can cause allergic reactions in some individuals. Diagnosing an allergy to this medication requires specific tests that assess the body's immune response.

• Skin Testing: Skin prick or intradermal testing may be performed under the supervision of a clinical immunology or allergy specialist (1). This test measures the level of IgE antibodies, which can indicate an allergic reaction.
• Blood Tests: Blood tests, such as full blood counts (FBC) and liver function tests (LFTs), are also conducted to ensure that the kidneys and liver are functioning properly and to check for any potential risks of infection (8)(9).
• Challenge Testing: Negative skin testing followed by a graded drug challenge has been shown to be safe, as reported in one study (3). This test involves administering increasing doses of co-trimoxazole to assess the body's response.
• Commercially Available Assays: Fluorescent enzyme immunoassays (FEIA) are available for in-vitro testing, although they may have lower sensitivity and specificity compared to other methods (2).

It is essential to note that there is no validated diagnostic test specifically designed for co-trimoxazole allergy. However, these tests can help identify allergies to specific drugs or substances.

References:

(1) BYH Thong · 2010 · Cited by 101 (2) C Basta · 2022 · Cited by 1 (3) C Basta · 2022 · Cited by 1 (8) May 11, 2022 (9) You will also need to have full blood counts (FBC)

Treatment Options for Co-trimoxazole Allergy

If you are allergic to co-trimoxazole, it is essential to avoid taking this medication in the future. However, if you have been accidentally exposed to co-trimoxazole or experience a severe reaction, medical attention should be sought immediately.

• Symptomatic Treatment: In cases of mild to moderate reactions, treatment may involve administering antihistamines or corticosteroids to alleviate symptoms such as hives, itching, and swelling.
• Desensitization Therapy: For individuals with a history of co-trimoxazole allergy, desensitization therapy can be considered. This involves gradually increasing exposure to the medication under medical supervision to build tolerance.
• Alternative Antibiotics: In cases where co-trimoxazole is required for treatment, alternative antibiotics such as penicillin or cephalosporins may be prescribed.

Important Considerations

• Always consult a healthcare professional before taking any medication, especially if you have a history of allergies.
• If symptoms worsen or new symptoms appear, seek medical attention promptly.
• Desensitization therapy should only be performed under the guidance of a qualified healthcare provider.

According to [1], various desensitization protocols are available for penicillin (benzylpenicillin, ampicillin), cephalosporins (ceftazidime, cefotaxime), cotrimoxazole, and other antibiotics. However, the decision to undergo desensitization therapy should be made on a case-by-case basis.

References

[1] BYH Thong · 2010 · Cited by 101 — Various desensitization protocols are available for penicillin (benzylpenicillin, ampicillin), cephalosporins (ceftazidime, cefotaxime), cotrimoxazole, ...

Based on the provided context, it appears that co-trimoxazole allergy has several differential diagnoses.

Common Differential Diagnoses

• Thrombotic thrombocytopenic purpura (TTP) [1]
• Glucose-6-phosphate-dehydrogenase (G6PD) deficiency [1]
• Stevens-Johnson syndrome (SJS) [7]
• Toxic epidermal necrolysis (TEN) [7]

Other Possible Differential Diagnoses

• Bullous insect bite reaction
• Bullous pemphigoid
• Idiopathic hyper-eosinophilic syndrome [7]
• Serum sickness, a rare manifestation of antibiotic allergy [8]

Symptoms and Presentation

• Urticaria (nettle rash) [9]
• Angioedema, causing swellings of deeper tissues [9]
• Anaphylaxis
• Fever, headache, neck pain, and other systemic symptoms in some cases [10]

It's essential to note that a thorough medical evaluation is necessary to determine the correct differential diagnosis for co-trimoxazole allergy. A healthcare professional should consider these possibilities and rule out other conditions based on patient history, physical examination, laboratory tests, and other diagnostic findings.

References: [1] Sircar et al., 2023 [7] MPharm et al., 2016 [8] Robinson et al., 2002 [9] Unknown author, 2021 [10] Context result 10