Hyposensitisation: Gradual Exposure to Allergens for Allergy Treatment

Hyposensitisation, also known as immunotherapy, is a treatment that involves gradually exposing a patient to increasing amounts of an allergen to reduce or eliminate their allergic response. The British National Formulary recommends this treatment for seasonal allergic hay fever and hypersensitivity to wasp and bee venoms that have not responded to anti-allergic drugs. However, it should be used with caution in patients with asthma.

The treatment typically lasts four weeks and can be administered through different dosing schedules, including conventional, modified rush, and rush. In a conventional schedule, injections are given weekly for 12 weeks, with the interval increasing stepwise to two, three, then four weeks. Maintenance treatment is then continued four weekly for at least three years.

Immunotherapy is recommended for patients with a history of severe systemic reactions or moderate systemic reactions with additional risk factors, such as a high serum tryptase or a high risk of stings, or whose quality of life is reduced by fear of venom allergy. Skin testing can be done, and measuring allergen-specific immunoglobulin E (IgE) antibodies is less sensitive.

Patients need referral to an immunotherapy specialist, and injections can be self-administered at home. However, a healthcare professional who can recognize and treat anaphylaxis should be present at the time of injection, and cardiopulmonary resuscitation facilities should be available. The patient should be observed for one hour after injection, and any symptoms, even if mild, need to be monitored until they resolve.

While local or systemic reactions may occur, including anaphylaxis, major side-effects are not a significant risk. However, risks are higher in people with asthma. Overall, hyposensitisation can be an effective treatment for allergies that have not responded to other therapies.

Skin Conditions: Allergic Contact Dermatitis, Atopic Eczema, Scabies, Hand, Foot and Mouth Disease, and Ringworm

Skin conditions can vary in their causes and symptoms. Allergic contact dermatitis is a delayed hypersensitivity reaction that occurs upon contact with an allergen, such as nickel, hair dyes, bleaches, perfumes, fragrances, and rubber antioxidants in gloves. Atopic eczema is a chronic skin condition that presents with red, itchy skin localized to the flexor surfaces and doesn’t normally develop vesicles. Scabies is a contagious skin condition caused by exposure to mites, which is very itchy and often starts between the fingers, but it would not normally flare up while at work. Hand, foot and mouth disease is a common childhood condition caused by the Coxsackievirus, characterized by a vesicular rash on the hands, feet, and mouth. Ringworm is a fungal skin infection that is usually circular with a silver scale and can be itchy, but it would be unlikely to cause bilateral hand symptoms and doesn’t cause the vesicular rash described here.

Understanding the Causes and Patterns of Allergies

Allergies have become increasingly prevalent in recent years, affecting up to 30-35% of people at some point in their lives. This rise is seen not only in developed countries but also in those undergoing development. The causes of allergies are multifactorial, with both environmental and genetic factors playing a role. Outdoor pollution, particularly diesel exhaust particles, has been linked to an increase in respiratory allergies. The hygiene hypothesis suggests that inadequate exposure to environmental micro-organisms during childhood may result in a tendency towards allergy. This is supported by studies showing that children with regular contact with farm animals have a lower incidence of allergy. The pattern of allergy is also changing, with a significant increase in food allergies, particularly among children. Immunotherapy for allergies should only be carried out in hospital where facilities for resuscitation are immediately available.

Managing Non-IgE-Mediated Cow’s’ Milk Protein Allergy in Infants

When dealing with a breastfed infant suspected of having non-IgE-mediated cows’ milk protein allergy, it is recommended to advise the mother to exclude cows’ milk from her diet for 2-6 weeks. During this period, calcium and vitamin D supplements may be prescribed to ensure the infant’s nutritional needs are met. After the exclusion period, reintroducing cows’ milk is advised to determine if it is the cause of the infant’s symptoms. If there is no improvement or the symptoms worsen, a referral to secondary care may be necessary.

For formula-fed or mixed-fed infants, replacing cow’s milk-based formula with hypoallergenic infant formulas is recommended. Extensively hydrolysed formulas (eHF) are typically the first option, and amino acid formulas are an alternative if the infant cannot tolerate eHFs or has severe symptoms. It is important to note that parents should not switch to soy-based formulas without consulting a healthcare professional, as some infants with cow’s’ milk protein allergy may also be allergic to soy.

In cases where there is faltering growth, acute systemic reactions, severe delayed reactions, significant atopic eczema with multiple food allergies suspected, or persistent parental concern, a referral to secondary care should be considered. With proper management and guidance, infants with non-IgE-mediated cow’s’ milk protein allergy can still receive adequate nutrition and thrive.

Symptoms of Acute Renal Transplant Rejection

Acute renal transplant rejection can occur after a kidney transplant and is characterized by reduced urine output, leading to oliguria and water retention. This can result in swelling of the limbs or abdomen and face. Malaise and fatigue are common symptoms, but they are also present in upper respiratory tract infections. Fever may also be present, but it is a nonspecific symptom found in many infections. Polyuria, or excessive urine output, is not typically seen in acute renal transplant rejection. Headache is a nonspecific symptom and may be present in both acute infections and graft rejection.

Skin prick testing is the preferred initial approach as it is cost-effective and can assess a wide range of allergens. Although IgE testing is useful in food allergy, it is specific IgE antibodies that are measured rather than total IgE levels.

Types of Allergy Tests

Allergy tests are used to determine the specific allergens that trigger an individual’s allergic reactions. There are several types of allergy tests available, each with its own advantages and limitations. The most commonly used test is the skin prick test, which is easy to perform and inexpensive. Drops of diluted allergen are placed on the skin, and a needle is used to pierce the skin. If a patient has an allergy, a wheal will typically develop. This test is useful for food allergies and pollen allergies.

Another type of allergy test is the radioallergosorbent test (RAST), which determines the amount of IgE that reacts specifically with suspected or known allergens. Results are given in grades from 0 (negative) to 6 (strongly positive). This test is useful for food allergies, inhaled allergens (such as pollen), and wasp/bee venom.

Skin patch testing is another type of allergy test that is useful for contact dermatitis. Around 30-40 allergens are placed on the back, and irritants may also be tested for. The patches are removed 48 hours later, and the results are read by a dermatologist after a further 48 hours.

Blood tests may be used when skin prick tests are not suitable, for example if there is extensive eczema or if the patient is taking antihistamines. Overall, the choice of allergy test depends on the individual’s specific needs and circumstances.

Common Infections in Kidney Transplant Patients

Kidney transplant patients are at a higher risk of infections due to immunosuppression. In the first month post-transplant, infections are similar to those in non-immunosuppressed individuals. However, in the one-month to six-month period, immunomodulating viruses like Cytomegalovirus (CMV), herpes simplex viruses, Epstein–Barr virus, and human herpesvirus-6, hepatitis A, B and C viruses, and human immunodeficiency virus (HIV) are most problematic. influenza can also cause respiratory symptoms, but routine annual administration of the injectable inactivated vaccine is recommended. Herpes simplex virus can cause severe lesions and even disseminated or visceral disease. Pneumonia and urinary infections are also common, and patients should receive appropriate immunisation and prophylactic antibiotics and antiviral drugs for a few months after transplantation. A small group of patients may experience persistence of viral infections and are at risk of opportunistic infections like cryptococcus, pneumocystis, listeria, and nocardia.

Understanding Rubella Immunity: Factors to Consider

Rubella, also known as German measles, is a viral infection that can have serious consequences for pregnant women and their unborn babies. To prevent maternal infection and congenital rubella syndrome, it is important to ensure immunity through vaccination or past infection. Here are some factors to consider when assessing rubella immunity:

– MMR Vaccine: The MMR vaccine is recommended for children and adults, with a two-dose schedule providing the best protection. A single dose can still offer high levels of immunity, but a booster may be necessary.
– Immunisation History: Individuals who have received rubella-containing vaccines in their country of origin may have some level of immunity, but it is important to verify their vaccination status. Those without a reliable history of immunisation should be assumed as unimmunised.
– Childhood History: A history of rubella in childhood may indicate immunity, but it can be difficult to diagnose. Other viral exanthems can have similar symptoms, so a clinical diagnosis may not be reliable.
– Rubella Antibodies: The presence of rubella-virus-specific IgG antibodies in the serum indicates immunity from past infection or immunisation. However, immunity can wear off over time, so it is important to check immunity levels before every pregnancy. Rubella-virus-specific IgM antibodies in the serum can indicate recent or current infection, but these antibodies can persist for up to 12 months after infection or immunisation.

By considering these factors, healthcare providers can help ensure that individuals are protected against rubella and its potential complications.

Post-Liver Transplant Patient Care: Important Considerations

Liver transplant patients require specialized care to ensure optimal outcomes. Here are some important considerations:

Encourage smoking cessation: Smoking can promote fibrosis and increase the risk of hepatoma development. Nicotine replacement therapy is a safe option.

Limit alcohol intake: For non-alcohol indications, maintaining alcohol intake below 14 units/week is appropriate to prevent significant relapse and graft damage.

Encourage exercise: Exercise can provide cardiovascular benefits and reduce the risk of osteoporosis. Strenuous exercise should be avoided for the first 12 months after transplant.

Consider statins: Pravastatin and atorvastatin are safe and effective for managing hypertriglyceridaemia following a liver transplant.

Use calcium channel blockers for hypertension: These drugs have minimal side effects and do not interact with calcineurin inhibitors like tacrolimus.

Venom allergy can cause local or systemic reactions, including anaphylaxis. Acute management is supportive, with anaphylaxis treated with adrenaline, steroids, and antihistamines. Referral to an allergy specialist is recommended for those with systemic reactions or suspected venom allergy. Venom immunotherapy may be recommended for those with a history of systemic reactions and raised levels of venom-specific IgE, but should not be performed in those without demonstrable venom-specific IgE or recent anaphylaxis. VIT has a high success rate in preventing systemic reactions and improving quality of life.