Detecting latent tuberculosis is crucial in controlling the disease, as up to 15% of adults with latent tuberculosis may develop active disease, and the risk may be even higher in children. In immunocompromised individuals, such as those who are HIV positive, the chance of developing active disease within 5 years of latent infection is up to 50%. The Mantoux test is a method of detecting previous exposure to the tuberculosis organism or BCG vaccination by causing a cell-mediated immune reaction. The interpretation of the test depends on factors such as BCG vaccination history, immune status, and concurrent viral infection. While a negative test in HIV-positive patients doesn’t exclude tuberculosis, a positive test at certain thresholds can indicate the need for treatment of latent tuberculosis. Indeterminate results may require further evaluation by a specialist. The use of IGT as a surrogate marker of infection can be useful in evaluating latent tuberculosis in BCG-vaccinated individuals, but it cannot distinguish between latent infection and active disease. NICE recommends different testing strategies based on age and risk factors, but the benefits of IGT over the Mantoux test in determining the need for treatment of latent tuberculosis are not certain. In children under 5 years, a positive test requires referral to a specialist to exclude active disease and consideration of treatment of latent tuberculosis.

Shingles Vaccination: Who Should Get It and When?

The national shingles immunisation programme aims to reduce the incidence and severity of shingles in older people. The vaccine is recommended for routine administration to those aged 70 years, but can be given up until the 80th birthday. Vaccination is most effective and cost-effective in this age group, as the burden of shingles disease is generally more severe in older ages. The vaccine is not routinely offered below 70 years of age, as the duration of protection is not known to last more than ten years and the need for a second dose is not known.

Zostavax® is the only shingles vaccine available in the UK, and is contraindicated in immunosuppressed individuals. Previous shingles is also a contraindication, as there is a natural boosting of antibody levels after an attack of shingles.

Clinical trials have shown that the vaccine reduces the incidence of shingles and post-herpetic neuralgia in those aged 60 and 70 years and older. However, it is important to note that the vaccine is only effective in reducing neuralgia.

In summary, the shingles vaccine is recommended for routine administration to those aged 70 years, but can be given up until the 80th birthday. It is contraindicated in immunosuppressed individuals and those with a history of shingles. While the vaccine is effective in reducing neuralgia, it is not a guarantee against shingles.

Understanding Myasthenia Gravis: Targets and Associations

Myasthenia gravis is an autoimmune disorder that affects the neuromuscular junction of skeletal muscles, leading to muscle weakness that worsens with exercise and improves with rest. In up to 90% of generalized cases, antibodies form against acetylcholine receptors (anti-AChR). However, other muscle antigens may also be targeted.

One such antigen is low-density lipoprotein receptor-related protein 4 (anti-LRP4), which is found in subsets of myasthenia gravis patients. Another target is muscle-specific receptor tyrosine kinase (anti-MuSK), which is detected in about half of generalized myasthenia gravis patients who are seronegative for anti-AChR antibodies. These patients may not respond to anticholinesterase drugs but do respond to steroid immunosuppression.

An association has also been observed between myasthenia gravis and human leukocyte antigen (HLA), although it is not the most likely target. Additionally, one-half of thymoma patients develop myasthenia gravis, while 15% of myasthenia gravis patients have thymomas. Non-AChR muscle autoantibodies reacting with striated muscle titin and RyR antigens are found in up to 95% of myasthenia gravis patients with a thymoma and in 50% of late-onset myasthenia gravis patients (onset at age of 50 years or later). These antibodies are usually associated with more severe myasthenia gravis.

Understanding the various targets and associations of myasthenia gravis can aid in diagnosis and treatment of this autoimmune disorder.

Understanding Food Allergies and Atopic Eczema in Children

Atopic eczema is a common skin condition that affects many children. While it can be managed with proper treatment, some cases may not respond to standard therapies. In these situations, food allergies should be considered as a possible contributing factor. According to the National Institute for Health and Care Excellence, children with moderate to severe atopic eczema that has not been controlled with optimum management, particularly if associated with gut dysmotility or failure to thrive, should be evaluated for food allergies.

Elevated levels of immunoglobulin E (IgE) are often associated with atopic eczema and may indicate allergies to food or environmental allergens. However, these allergies may not be directly related to the eczema. While exclusive breastfeeding has been recommended to prevent the development of atopic eczema in susceptible infants, there is no evidence to support this claim.

Allergy tests, such as prick tests and radioallergosorbent tests (RAST), may be used to identify potential allergens. However, false positives are common in individuals with atopic eczema due to the skin’s excessive sensitivity. If a true allergy is identified and exposure to the allergen worsens the eczema, removing the allergen may improve the condition.

In summary, understanding the relationship between food allergies and atopic eczema is important for managing this common condition in children. Proper evaluation and treatment can help improve symptoms and quality of life.

Antihistamines: Uses and Limitations in Various Skin Conditions

Urticaria, Chickenpox, atopic eczema, local reactions to insect stings, and general pruritus are common skin conditions that may benefit from antihistamines. However, the effectiveness of antihistamines varies depending on the underlying cause and the individual’s response.

For a 15-year-old girl with acute urticaria, non-sedating H1 antihistamines are the first-line treatment. If the first antihistamine is not effective, a second one may be tried.

A 4-year-old girl with Chickenpox may benefit from emollients and sedating antihistamines to relieve pruritus. Calamine lotion may also be used, but its effectiveness decreases as it dries.

Antihistamines are not routinely recommended for atopic eczema, but a non-sedating antihistamine may be tried for a month in severe cases or when there is severe itching or urticaria. Sedating antihistamines may be used for sleep disturbance.

For a 50-year-old woman with a local reaction to a wasp sting, antihistamines are most effective when used immediately after the sting. After 48 hours, they are unlikely to have a significant impact on the local reaction.

Finally, for a 65-year-old man with general pruritus but no rash, antihistamines may be prescribed, but their effectiveness is limited as histamine may not be the main cause of the pruritus.

Managing Women’s Health after Renal Transplant: Contraception, Cancer Screening, and Vaccinations

Women who have undergone renal transplant and are of childbearing age should use effective contraception to prevent unintended pregnancy. The most effective methods include intrauterine contraceptive devices, etonogestrel implants, and depot medroxyprogesterone acetate. The latter is particularly suitable as it doesn’t interact with immunosuppressive drugs commonly used in transplant patients. While pregnancy is possible after a renal transplant, it is recommended to wait for at least a year and plan it carefully. Women should also manage their cardiovascular risk factors and keep up-to-date with vaccinations and cancer screening.

Renal transplant recipients have a higher incidence of cancer than the general population, so regular cancer screening is essential. Breast screening typically starts at 50 years, while cervical screening may not require additional tests. Warfarin is unlikely to be prescribed after a renal transplant, but if necessary, careful monitoring is required. Live vaccines, including Zostavax® shingles vaccine, should be avoided due to the risk of lower efficacy and immunosuppression. Instead, Shingrix® vaccine can be used where indicated.

Administering Adrenaline: Dosage and Site of Injection

When administering adrenaline, it is recommended to inject it intramuscularly in the anterolateral aspect of the middle third of the thigh. This site is considered safe, easy, and effective. The standard adult dose is 0.5 ml 1:1000, while children aged 6-12 years should receive 0.3 ml. For younger children, the dose varies from 0.15 ml for those aged 6 months to 6 years, and 0.1-0.15 ml for infants younger than 6 months. If there is no improvement after 5 minutes, a repeat dose of intramuscular adrenaline may be necessary. In some cases, patients may require intravenous adrenaline, which should only be administered by trained and experienced medical professionals such as anaesthetists and A&E consultants.

Sulfasalazine may cause a reaction in patients who are allergic to aspirin.

Sulfasalazine: A DMARD for Inflammatory Arthritis and Bowel Disease

Sulfasalazine is a type of disease modifying anti-rheumatic drug (DMARD) that is commonly used to manage inflammatory arthritis, particularly rheumatoid arthritis, as well as inflammatory bowel disease. This medication is a prodrug for 5-ASA, which works by reducing neutrophil chemotaxis and suppressing the proliferation of lymphocytes and pro-inflammatory cytokines.

However, caution should be taken when using sulfasalazine in patients with G6PD deficiency or those who are allergic to aspirin or sulphonamides due to the risk of cross-sensitivity. Adverse effects of sulfasalazine may include oligospermia, Stevens-Johnson syndrome, pneumonitis/lung fibrosis, myelosuppression, Heinz body anaemia, megaloblastic anaemia, and the potential to color tears and stain contact lenses.

Despite these potential side effects, sulfasalazine is considered safe to use during pregnancy and breastfeeding, making it a viable option for women who require treatment for inflammatory arthritis or bowel disease.

Oral allergy syndrome is closely associated with pollen allergies and exhibits seasonal fluctuations. It occurs when allergens in certain foods cross-react with pollens, causing the body to react to the food proteins as if they were pollen. This results in a localized reaction around the mouth, such as an itchy mouth or throat, and sometimes hives. As the patient experiences symptoms with various fruits, it is not a pure kiwi allergy. Urticaria is characterized by an itchy rash triggered by an allergen, but there is no mention of a rash in this case. Anaphylaxis is a severe allergic reaction that causes swelling of the throat and tongue, as well as breathing difficulties. However, since there is only mild lip swelling and no breathing difficulties, anaphylaxis is unlikely.

Understanding Oral Allergy Syndrome

Oral allergy syndrome, also known as pollen-food allergy, is a type of hypersensitivity reaction that occurs when a person with a pollen allergy eats certain raw, plant-based foods. This reaction is caused by cross-reaction with a non-food allergen, most commonly birch pollen, where the protein in the food is similar but not identical in structure to the original allergen. As a result, OAS is strongly linked with pollen allergies and presents with seasonal variation. Symptoms of OAS typically include mild tingling or itching of the lips, tongue, and mouth.

It is important to note that OAS is different from food allergies, which are caused by direct sensitivity to a protein present in food. Non-plant foods do not cause OAS because there are no cross-reactive allergens in pollen that would be structurally similar to meat. Food allergies may be caused by plant or non-plant foods and can lead to systemic symptoms such as vomiting and diarrhea, and even anaphylaxis.

OAS is a clinical diagnosis, but further tests can be used to rule out other diagnoses and confirm the diagnosis when the history is unclear. Treatment for OAS involves avoiding the culprit foods and taking oral antihistamines if symptoms develop. In severe cases, an ambulance should be called, and intramuscular adrenaline may be required.

In conclusion, understanding oral allergy syndrome is important for individuals with pollen allergies who may experience symptoms after eating certain raw, plant-based foods. By avoiding the culprit foods and seeking appropriate medical care when necessary, individuals with OAS can manage their symptoms effectively.

Autoantibodies and their Association with Autoimmune Diseases

Autoantibodies are antibodies that target the body’s own tissues and cells. They are often associated with autoimmune diseases, which occur when the immune system mistakenly attacks healthy cells and tissues. Here are some common autoantibodies and their association with autoimmune diseases:

1. Rheumatoid factor: This autoantibody is found in 60-70% of patients with rheumatoid arthritis (RA) and in 5% of the general population. It may also be elevated in other autoimmune diseases. Testing for rheumatoid factor is recommended in people with suspected RA who have synovitis on clinical examination.

2. Antinuclear antibody: This autoantibody binds to the contents of the cell nucleus. It is present in almost all people with systemic lupus erythematosus and is also found in patients with other autoimmune diseases such as rheumatoid arthritis, scleroderma, Sjögren’s syndrome, polymyositis, and certain forms of chronic active hepatitis.

3. Antimitochondrial antibody: This autoantibody is present in 90-95% of patients with autoimmune liver disease, primary biliary cholangitis, and also in 0.5% of the general population. It is also found in about 35% of patients with primary biliary cirrhosis.

4. Antiphospholipid antibodies: These autoantibodies are associated with antiphospholipid syndrome, an autoimmune, hypercoagulable state that can cause arterial and venous thrombosis as well as pregnancy-related complications such as miscarriage, stillbirth, preterm delivery, and severe preeclampsia.

5. HLA-B27 antigen: This antigen is strongly associated with ankylosing spondylitis, as well as other diseases such as psoriasis, reactive arthritis, and inflammatory bowel disease. Its prevalence varies in the general population according to racial type.

In conclusion, autoantibodies can provide important diagnostic and prognostic information in autoimmune diseases. Testing for these antibodies can help healthcare providers make accurate diagnoses and develop effective treatment plans.