Allergic reactions to anaesthesia giving false positive and false negative results. Although complications during anaesthesia are rare, potentially life-threatening consequences may occur if an anaphylactic reaction develops. The severity of the reaction whilst under anaesthesia is because the anaesthetist is only made aware of the allergy when it is severe enough to compromise the cardiovascular system and the respiratory system. At this stage, there is little time to manage the situation and recognise the severity of the condition. The immediate management of the issue consists of three processes: Since the full withdrawal of the offending substance is near impossible, the administration of adrenalin is
Henna a person has had a black henna tattoo and later dyes their hair with chemical hair dye, the allergic reaction may be life-threatening and require hospitalization. Because of the epidemic of PPD allergic reactions, chemical hair dye products now post warnings on the labels: "Temporary black henna tattoos may increase your risk of allergy. Do not colour your hair if: ... – you have experienced a reaction to a temporary black henna tattoo in the past." PPD is illegal for use on skin in western countries, though enforcement is difficult. Physicians have urged governments to legislate against black henna because