His doctor often prescribes antibiotics (macrolides) associated with other drugs (antitussive drugs, anti-pyretics, nasal vasodilators) to treat these sore throats. However, almost each time, within 48 hours after beginning the antibiotic treatment, a generalised erythema appears that is accompanied by fever.
For the last sore throat, Thierry consulted claiming an allergy to the antibiotics prescribed by his doctor. In fact, one of his colleagues, allergic to antibiotics, presented the same symptoms.
However, since an allergy to macrolide type antibiotics is rather rare, the doctor carried out intensive questioning during which Thierry mentioned similar symptoms after taking a drug whose name he no longer remembered. Thierry then mentioned that since his sore throats last for too long, he wanted to speed things up by absorbing pseudo-ephedrine, a substance found in a great many over-the-counter pharmaceutical drugs and that clears the nose by constriction of the small oedematised vessels.
The allergological exploration demonstrated that Thierry was allergic to pseudo-ephedrine and not the antibiotic prescribed to treat his sore throat, as he and his colleague thought. To demonstrate this, it was necessary to carry out skin patch-tests under hospital monitoring, for each of the drugs and then reintroduce the macrolide involved.
Self-medication may be a source of unpredictable reactions such as the allergic reaction described above. In the present case, the allergen was all the more difficult to identify since it came from a drug taken peripherally to the treatment prescribed by the doctor which could have been the cause of the allergic reaction. Finally, even if a neighbour, colleague, friend, etc., has a similar experience, it does not mean that the same effects are due to the same causes. Each individual has a specific sensitivity. Therefore, for all allergic reactions, it is necessary to get in touch with a medical team and rely on it.