Question

1. A 31-year-old male develops a severe full-body rash after receiving penicillin. He is certain that he has never received this antibiotic in the past. Summarize the immunologic reaction that is occurring in this patient, and discuss one hypothesis that would explain why the symptoms occurred when he never was prescribed the drug before. 2. Trace the course of a pollen grain through sensitization and provocation in type I allergies, discussing the role of mast cells, basophils, IgE, and allergic mediators.

Answer 1

Answer 1:

If the person is certain about the non-exposure of penicillin ever before. It may be possible that the kind of symptoms that appeared can be due to pseudo allergic reaction generated by Complement activation related pseudo allergy. The biochemical cascade reactions occur in this involve these steps:

• Firstly, the complement activation system gets activated which releases due to primary mediators
• In response to that blood cells and secretory cells like basophils, mast cells and other types of phagocytic cells are secreted   as a result the anaphylatoxins bind to them
• Leading to the production of the second group of mediators i.e. histamines, cytokines, etc.
• This forms the general outline of an immunological response to a pseudo allergic reaction. Pseudo allergy does not pose an antigen-antibody reaction but it does elicit histamine release in response to complement activation.

The possibilities that drew the attention towards pseudo allergic response and occurrence of symptoms are:

• Patients at the age between 29-40 are at increased risk of having anaphylaxis.
• The incident frequency of true penicillin allergy is generally less than 0.05% only.
• On lab testing ( skin testing ) the reported large amount of patients ~ 90% who believed themselves of having penicillin allergy showed negative outcomes and had only anaphylaxis that resulted into urticaria (common name is hives, pink rashes and swelling that may itch but lasts only for 24 hours and then vanish), angioedema and digestive gastro related issues.
• Hives are common in individuals. It is said that at least once in a lifetime due to some reason or exposure of something person may develop hives. It usually occurs among 10-20% of the population who take some medications.
• Pseudo allergy does occur after the first exposure to medication and involves an anaphylactic reaction. It is often unpredictable to happen.
• Penicillin reactions generally occur on those individuals who possess some previous exposure penicillin treatment with preformed IgE resulting in acute or sub-acute responses.