Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome usually presents two to six weeks after treatment with a drug implicated in this disorder. However, in some cases, it can present more than eight weeks after the initiation of an implicated medication. This is a type 4 drug hypersensitivity reaction in which any internal organ may be involved. While the liver is commonly involved, cardiac involvement is not unheard of. Comorbidities and multiorgan involvement may obscure the diagnosis, and Registry of Severe Cutaneous Adverse Reactions (RegiSCAR) criteria are a useful diagnostic aid. It is best treated by withdrawing the offending agent and administering systemic steroids. Oxidative stress is high in DRESS syndrome. Hepatoprotection is a priority in all patients and yields a better prognosis.

Drug hypersensitivity reactions (DHRs) manifested as vasculitis are rare. Antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), sulphonamides, diuretics, immunosupressants and anticonvulsants are the most common culprits for drug-induced leukocytoclastic vasculitis (LCV) but there is scarce information about barbiturates. We present a case of 53-year-old female with severe vasculitis after phenobarbital- and NSAIDs-containing medications use. The preliminary diagnosis of drug-induced vasculitis was made based on anamnestic and clinical data. Further examinations confirmed the diagnosis of LCV and excluded other more common causes of vasculitis. The causative significance of used medications was assessed by long-term observation of the patient after the reaction, including the drug challenge series and Naranjo\'s Adverse Drug Reaction Probability Scale. It was concluded that phenobarbital is the most probable culprit drug. The patient\'s data were included in the Armenian Registry of Patients with Severe DHRs. Since then, the patient has avoided only barbiturate-containing drugs and no reactions were noted. Thus, the case indicates that even with limited diagnostic capabilities, the final diagnosis of rare drug-induced LCV and even rarer culprit drug can be established by comparing the available data. Awareness about phenobarbital and proper recording of the case are important in the management and prevention of DHRs manifested as vasculitis.

Perioperative hypersensitivity reactions vary from mild to potentially fatal anaphylaxis, resulting in significant morbidity and mortality. Most of the perioperative hypersensitivity and allergic reactions are attributed to antibiotics, antiseptic solutions, latex, and opioids. In the current thrust for opioid-free anesthesia, owing to its multiple advantages, paracetamol and nonsteroidal antiinflammatory agents play a significant role in multi-modal pain and inflammatory response management. Nearly nine out of ten individuals experience postoperative pain, one-third experience postoperative nausea and vomiting, and one-fourth experience fever, irrespective of surgery and type of anesthesia, often as an inflammatory response. While perioperative hypersensitivity reactions are common, a patient allergic to multiple commonly used drugs for the treatment of pain, fever, acid-peptic disorder, and nausea and vomiting is scarce. Such cases pose a great challenge in perioperative management. A 14-year-old male child with a traumatic foot drop planned for tibialis posterior tendon transfer developed an allergic reaction with mild fever following an injection of Ranitidine and Ondansetron in the preoperative area. Surgery was deferred and was investigated for allergy profile testing for commonly used drugs, which showed high IgE levels and moderate to severe hypersensitivity for diclofenac and paracetamol. The patient was operated on after one month under spinal anesthesia, avoiding ranitidine, ondansetron, diclofenac, and paracetamol. The following morning, he developed a high-grade fever (102.3° F), which did not resolve with conservative measures. Hypersensitivity and allergic reactions to NSAIDs are reported in the literature. While there are multiple drugs available as NSAIDs, cross-sensitivity or allergy to other drugs within the same group, and even chemically related groups, is also another possibility that needs to be considered while managing such patients. Mefenamic acid controlled the fever, and the child was discharged home after 48 hours of observation. However, the case posed a great perioperative management dilemma; the present report intends to highlight and discuss it.