Adrenaline can be given in cases of life-threatening anaphylactic reactions, even if there are certain conditions that may make it less advisable. These conditions include coronary artery disease, uncontrolled hypertension, serious ventricular arrhythmias, and the second stage of labor. Despite these relative contraindications, adrenaline may still be administered to address the immediate danger posed by anaphylaxis.

Urticaria is a condition characterized by a raised, itchy rash on the skin and mucous membranes. It can be localized or widespread and affects about 15% of people at some point in their lives. There are two forms of urticaria: acute and chronic, with the acute form being more common.

In about 50% of cases of acute urticaria, a specific trigger can be identified. Common triggers include allergies (such as foods, bites, stings, and drugs), skin contact with irritants (like chemicals, nettles, and latex), physical stimuli (such as firm rubbing, pressure, and extremes of temperature), and viral infections.

The main skin lesion seen in urticaria is called a wheal or wheel. Wheals typically have three characteristics: a central swelling that can be red or white in color, surrounded by a red area (known as the flare), and they are usually very itchy, sometimes accompanied by a burning sensation. Wheals are temporary and usually disappear within 1 to 24 hours, returning the skin to its normal appearance.

Wheals can vary in size, ranging from a few millimeters to lesions as large as 10 cm in diameter. They can appear as single lesions or multiple ones, and sometimes they merge together to form large patches. In some cases, urticaria can also cause swelling of the soft tissues in the eyelids, lips, and tongue, known as angioedema.

Corticosteroids can be beneficial in preventing or reducing prolonged reactions. According to the current APLS guidelines, the recommended doses of hydrocortisone for different age groups are as follows:

– Children under 6 months: 25 mg administered slowly via intramuscular (IM) or intravenous (IV) route.
– Children aged 6 months to 6 years: 50 mg administered slowly via IM or IV route.
– Children aged 6 to 12 years: 100 mg administered slowly via IM or IV route.
– Children over 12 years: 200 mg administered slowly via IM or IV route.
– Adults: 200 mg administered slowly via IM or IV route.

It is important to note that the most recent ALS guidelines do not recommend the routine use of corticosteroids for treating anaphylaxis in adults. However, the current APLS guidelines still advocate for the use of corticosteroids in children to manage anaphylaxis.

The management of anaphylaxis involves several important steps. First and foremost, it is crucial to ensure proper airway management. Additionally, early administration of adrenaline is essential, preferably in the anterolateral aspect of the middle third of the thigh. Aggressive fluid resuscitation is also necessary. In severe cases, intubation may be required. However, it is important to note that the administration of chlorpheniramine and hydrocortisone should only be considered after early resuscitation has taken place.

Adrenaline is the most vital medication for treating anaphylactic reactions. It acts as an alpha-adrenergic receptor agonist, which helps reverse peripheral vasodilatation and reduce oedema. Furthermore, its beta-adrenergic effects aid in dilating the bronchial airways, increasing the force of myocardial contraction, and suppressing histamine and leukotriene release. Administering adrenaline as the first drug is crucial, and the intramuscular (IM) route is generally the most effective for most individuals.

The recommended doses of IM adrenaline for different age groups during anaphylaxis are as follows:

– Children under 6 years: 150 mcg (0.15 mL of 1:1000)
– Children aged 6-12 years: 300 mcg (0.3 mL of 1:1000)
– Children older than 12 years: 500 mcg (0.5 mL of 1:1000)
– Adults: 500 mcg (0.5 mL of 1:1000)

Anaphylaxis is a severe allergic reaction that is caused by the immune system overreaction to a specific allergen. This reaction is classified as a Type I hypersensitivity reaction, which means it is mediated by the IgE antibodies.

Further Reading:

Anaphylaxis is a severe and life-threatening hypersensitivity reaction that can have sudden onset and progression. It is characterized by skin or mucosal changes and can lead to life-threatening airway, breathing, or circulatory problems. Anaphylaxis can be allergic or non-allergic in nature.

In allergic anaphylaxis, there is an immediate hypersensitivity reaction where an antigen stimulates the production of IgE antibodies. These antibodies bind to mast cells and basophils. Upon re-exposure to the antigen, the IgE-covered cells release histamine and other inflammatory mediators, causing smooth muscle contraction and vasodilation.

Non-allergic anaphylaxis occurs when mast cells degrade due to a non-immune mediator. The clinical outcome is the same as in allergic anaphylaxis.

The management of anaphylaxis is the same regardless of the cause. Adrenaline is the most important drug and should be administered as soon as possible. The recommended doses for adrenaline vary based on age. Other treatments include high flow oxygen and an IV fluid challenge. Corticosteroids and chlorpheniramine are no longer recommended, while non-sedating antihistamines may be considered as third-line treatment after initial stabilization of airway, breathing, and circulation.

Common causes of anaphylaxis include food (such as nuts, which is the most common cause in children), drugs, and venom (such as wasp stings). Sometimes it can be challenging to determine if a patient had a true episode of anaphylaxis. In such cases, serum tryptase levels may be measured, as they remain elevated for up to 12 hours following an acute episode of anaphylaxis.

The Resuscitation Council (UK) provides guidelines for the management of anaphylaxis, including a visual algorithm that outlines the recommended steps for treatment.
https://www.resus.org.uk/sites/default/files/2021-05/Emergency%20Treatment%20of%20Anaphylaxis%20May%202021_0.pdf

The management of anaphylaxis involves several important steps. First and foremost, it is crucial to ensure proper airway management. Additionally, early administration of adrenaline is essential, preferably in the anterolateral aspect of the middle third of the thigh. Aggressive fluid resuscitation is also necessary. In severe cases, intubation may be required. However, it is important to note that the administration of chlorpheniramine and hydrocortisone should only be considered after early resuscitation has taken place.

Adrenaline is the most vital medication for treating anaphylactic reactions. It acts as an alpha-adrenergic receptor agonist, which helps reverse peripheral vasodilatation and reduce oedema. Furthermore, its beta-adrenergic effects aid in dilating the bronchial airways, increasing the force of myocardial contraction, and suppressing histamine and leukotriene release. Administering adrenaline as the first drug is crucial, and the intramuscular (IM) route is generally the most effective for most individuals.

The recommended doses of IM adrenaline for different age groups during anaphylaxis are as follows:

– Children under 6 years: 150 mcg (0.15 mL of 1:1000)
– Children aged 6-12 years: 300 mcg (0.3 mL of 1:1000)
– Children older than 12 years: 500 mcg (0.5 mL of 1:1000)
– Adults: 500 mcg (0.5 mL of 1:1000)

Urticaria is a common condition that causes a red, raised, itchy rash on the skin and mucous membranes. It can be localized or spread out. Approximately 15% of people will experience urticaria at some point in their lives. There are two forms of urticaria: acute and chronic, with acute being more common.

According to the current guidelines from the National Institute for Health and Care Excellence (NICE), individuals seeking treatment for urticaria should be offered a non-sedating antihistamine from the second-generation category. Examples of second-generation antihistamines include cetirizine, loratadine, fexofenadine, desloratadine, and levocetirizine.

It is no longer recommended to use conventional first-generation antihistamines like promethazine and chlorpheniramine for urticaria. These medications have short-lasting effects and can cause sedation and anticholinergic side effects. They may also interfere with sleep, learning, and performance, as well as interact negatively with alcohol and other medications. In some cases, lethal overdoses have been reported. Terfenadine and astemizole should also be avoided as they can be harmful to the heart when combined with certain drugs like erythromycin and ketoconazole.

It is advisable to avoid antihistamines during pregnancy if possible. There is a lack of systematic studies on their safety during pregnancy. However, if an antihistamine is necessary, chlorpheniramine is the recommended choice. For breastfeeding women, loratadine or cetirizine are preferred options.

The connection between latex sensitivity and food allergy is commonly known as the latex-fruit syndrome. Foods that have been found to be allergenic in relation to latex are categorized into high, moderate, or low risk groups.

High risk foods include banana, avocado, chestnut, and kiwi fruit.

Moderate risk foods include apple, carrot, celery, melon, papaya, potato, and tomato.

Citrus fruits and pears are considered to have a low risk of causing allergic reactions in individuals with latex sensitivity.

When dealing with an anaphylactic reaction, it is important to remove the trigger if it is easily accessible. However, it is not realistic to try and remove a peanut that has already been swallowed, and it is advised against attempting to induce vomiting in the patient.

In cases where an anaphylactic reaction has been confirmed, it is crucial to administer 500 micrograms of adrenaline immediately.

Hereditary angioedema is a condition caused by a lack of C1 esterase inhibitor, a protein that is part of the complement system. It is typically inherited in an autosomal dominant manner. Symptoms usually start in childhood and continue sporadically into adulthood. Attacks can be triggered by minor surgical procedures, dental work, and stress. The main clinical signs of hereditary angioedema include swelling of the skin and mucous membranes, with the face, tongue, and extremities being the most commonly affected areas. There is often a tingling sensation before an attack, sometimes accompanied by a non-itchy rash.

Angioedema and anaphylaxis resulting from C1 esterase inhibitor deficiency do not respond to adrenaline, steroids, or antihistamines. Treatment requires the use of C1 esterase inhibitor concentrate or fresh frozen plasma, both of which contain C1 esterase inhibitor. In situations that may trigger an attack, short-term prophylaxis can be achieved by administering C1 esterase inhibitor or fresh frozen plasma infusions prior to the event. For long-term prevention, androgenic steroids like stanozolol or antifibrinolytic drugs such as tranexamic acid can be used.