<prompt> Answer this question truthfullyWhat is the definition of an anaphylactoid reaction?  <response>: <reason> The clinical features are quite similar to anaphylaxis, however the presentation is almost always milder. Most commonly the syndrome begins with involvement of the skin, usually as pruritus, flush, urticaria, or angioedema. Paresthesia, itching of pharynx and genital area, and feeling of anxiety are common symptoms. Almost all organ systems may be involved as explained below:RespiratorySneezing or rhinorrhea is the earliest manifestation.Hoarseness or throat tightnessCough and wheezing Change of voice dysphonia Dyspnea due to laryngeal obstruction Cyanosis or even respiratory arrest may occurGastrointestinalNausea and cramping vomiting and diarrhea Micturition and defecationCardiovascularTachycardia Hypotension Arrythmia Shock Cardiac arrestThe following system of grading is sometimes used to grade the severity of reactions:Symptoms Skin Abdomen Respiratory Cardiovascular Grade I Pruritus, flush, urticaria, angioedema - - - Grade II Pruritus, flush, urticaria, angioedema Nausea, cramping Rhinorrhea, hoarseness, dyspnea Tachycardia, arrhythmia Grade III Pruritus, flush, urticaria, angioedema Vomiting, defecation, diarrhea Laryngeal edema, bronchospasm, cyanosis Shock Grade IV Pruritus, flush, urticaria, angioedema Vomiting, defecation, diarrhea Respiratoy arrest Cardiac arrestAdapted from Ring and Mesmer 