Allergic shock

The vasodilatory effect of Hi-receptor stimulation is mainly due to an endothelial release of nitric oxide, which is able to activate the soluble guany-late cyclase in vascular smooth muscle cells. This effect is mainly responsible for the erythema seen after injection (insect sting) of histamine. Furthermore, it is responsible, together with the increased capillary permeability, for the cardiovascular symptoms seen in anaphylactic or allergic shock. 

Metamizol is relatively free of acute side-effects but in rare cases may induce severe and life-threatening allergic reactions such as agranulocytosis, allergic skin reactions and allergic shock. Therefore, the compound is not used in the UK, US or Scandinavian countries. 

Commens CA+, Arch Dermatol 124, I 78 Toxic-allergic shock... 

Wang MH. One case of allergic shock caused by Banlangen soft capsule. Anhui Yi Yao 2010 14(2) 247. 

Chen W. One case of allergic shock was caused by Xiyanping injection. Shou Du Yi Yao 2010 (11) 44. 

He M. One case of allergic shock and drug rash caused by external application of Yadanzi. Xinan Guo Fang Yi Yao 2010 20(11) 1190. 

The explanations are all compatible because severe allergic reactions are accompanied by (1) a marked enlargement (dilation) of the blood vessels, and a great drop in the blood pressure and (2) a speeding up of the heart rate as the heart attempts to maintain the normal circulation of blood. Deficiencies of selenium and vitamin E may weaken the heart muscle so that it cannot cope with the increased workload brought about by a state of allergic shock. 

The penicillins in general, ate renowned for their lack of toxicity. The most common adverse effect of the use of penicillins is an allergic reaction which can change from a mild rash to fatal anaphylactic shock in rate cases. AH penicillins cross the placenta and ate excreted in maternal milk. However, the relative freedom from toxicity tenders these compounds valuable agents during pregnancy and lactation. 

Platelet activating factor (PAF) was first identified by its ability (at low levels) to cause platelet aggregation and dilation of blood vessels, but it is now known to be a potent mediator in inflammation, allergic responses, and shock. PAF effects are observed at tissue concentrations as low as 10 M. PAF causes a dramatic inflammation of air passages and induces asthma-like symptoms in laboratory animals. Toxic-shock syndrome occurs when fragments of destroyed bacteria act as toxins and induce the synthesis of PAF. This results in a drop in blood pressure and a reduced... 

The term anaphylactic shock describes a severe generalized type I allergic reaction associated with cardiovascular shock, airway constriction and heart arrhythmias, which, if left untreated, may cause death. 

Anaphylactic shock is an extremely serious allergic drug reaction that usually occurs shortly after the administration of a drug to which the individual is sensitive This type of allergic reaction requires immediate medical attention. Symptoms of anaphylactic shock are listed in Table 1-2. 

Allergic reactions (anaphylactic shock, angioneurotic edema) ... 

The ghicocorticoids are used as replacement therapy for adrenocortical insufficiency, to treat allergic reactions, collagen diseases (eg, systemic lupus erythematosus), dermatologic conditions, rheumatic disorders, shock, and other conditions (see Display 50-1). The anti-inflammatory activity of these hormones make them valuable as anti-inflammatories and as immunosuppressants to suppress inflammation and modify the immune response... 

Plasma proteins are contraindicated in those with a history of allergic reactions to albumin, severe anemia, or cardiac failure in the presence of normal or increased intravascular volume and in patients on cardiopulmonary bypass. Plasma protein fractions are used cautiously in patients who are in shock or dehydrated and in those with congestive cardiac failure or hepatic or renal failure. These solutions are Pregnancy Category C drugp and are used cautiously during pregnancy and lactation. 

Anaphylaxis is the most dramatic and potentially catastrophic manifestation of allergic disorders. It can affect virtually any organ including the cardiovascular system. Cardiovascular collapse and hypotensive shock in anaphylaxis have been attributed to peripheral vasodilation, enhanced vascular permeability and plasma leakage, rather than any direct effect on the myocardium. However, there is increasing experimental and clinical evidence that the human heart is a site and target of anaphylaxis. 

Radio contrast media may cause serious immediate pseudo allergic reactions such as urticaria/angioedema, bron-chospasm, shock, and death. These reactions have been reduced with the introduction of non-ionic, lower-osmolality products. Because a small percentage of patients who have reacted previously to radiocontrast media will react if re-exposed, several steps should be taken to prevent reactions, including ... 

The older test is the pin prick test where a small quantity of the antigen is placed under the skin. If there is an allergic reaction a wheal and flare, i.e. a hive, will appear. The pin prick test is not suitable for those who undergo anaphylactic shock. 

As a bacterial protein, streptokinase is viewed by the human immune system as an antigenic substance. In some cases, its administration has elicited allergic responses that have ranged from mild rashes to more serious anaphylactic shock (an extreme and generalized allergic response characterized by swelling, constriction of the bronchioles, circulatory collapse and heart failure). 

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