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Showing posts with label immunology. Show all posts
Showing posts with label immunology. Show all posts

Monday, January 29, 2018

What is DRESS Syndrome?

DRESS (drug reaction with eosinophilia and systemic symptoms) is a poorly understood syndrome that has an unknown prevalence in the pediatric population because it is often missed by doctors. 
Symptoms include fever, an itchy rash covering over half the body, enlarged lymph nodes, and inflammation of the liver. A blood test reveals increased white blood cells, "atypical lymphocytes" (abnormally large and irregular lymphocytes because they are infected with the virus), and elevated eosinophils. 

What causes it? There have been links to both herpesvirus (including oral and genital herpes, epstein barr virus and roseola virus) and a couple months after starting certain anti-seizure medications. Bad cases will involve >90% of the skin and affect multiple organs such as the kidneys, and there may be involvement of the mucosal lining of the mouth and lips which can mimic life threatening drug and infectious reactions known as Stevens Johnson Syndrome and Toxic Epidermal Necrolysis.
It is very difficult to avoid getting this syndrome, as it is unknown why some patients get it and others do not. It can take months to fully recover from DRESS syndrome. The treatment, if caused by a medication, is to stop that medication. Most patients get IV or topical steroids to calm the immune system. 
Most often, pediatric rashes are harmless. In rare cases such as this, however, some detective work is required to make a swift and proper diagnosis.

Thursday, November 17, 2016

New Antibody Discovered Highly Effective Against HIV

A recent article in the Journal of Immunology highlighted a groundbreaking discovery in the fight against the human immunodeficiency virus (HIV). Funded by the National Institute of Health (NIH) and the National Institute of Allergy and Infectious Diseases (NIAID), Dr. Mark Connors and his team discovered an antibody named N6 that appeared to neutralize over 98 percent of the HIV isolates tested. What is particularly promising was the ability to eradicate even the known resistant strains.

To date, the discovery of a vaccine has been difficult due to the rapidly changing structure of the proteins on the surface of the virus. The N6 antibody, however, is particularly adept at binding a more consistent portion of the virus called the CD4 binding site, which allows it to attach to human cells.
The N6 antibody joins the ranks of the VRC01 antibody, which was discovered in 2010 and is in clinical trials, but it's effectiveness is far greater. This may translate to a vaccine that will finally prevent HIV from evading our immune system, saving countless lives and cutting healthcare costs. 


Tuesday, July 1, 2014

Asthma in children


Asthma is a condition of the small airways of our lungs in which hypersensitive cells are aggravated by environmental substances, leading to inflammation, swelling and poor air flow. It is estimated that 70% of cases are caused by allergic substances such as dust, pollen and pet dander. Other causes include viral illnesses, exercise and cough.



It’s estimated that in the United States, 1 in 10 children younger than 18 years suffer from asthma. Many children with asthma have experienced what is known in dermatology as the “atopic march”, which is essentially a trifecta of asthma, atopic dermatitis (eczema), food allergy and allergic rhinitis (hay fever). Additionally, having asthma makes airways of children vulnerable, putting them at increased risk for diseases like pneumonia, influenza and obstructive sleep apnea.

Signs of asthma in children younger than 2 years old include noisy breathing, grunting and cough while the classic signs in children with are wheezing, chest tightness, cough and difficulty breathing.

Pediatricians will attempt to get specific information regarding the asthma in order to both determine the level of severity and prescribe the most appropriate course of treatment. Questions asked include daytime or nighttime cough, possible triggers (such as viral illness, changing seasons, exercise, etc) and previous episodes. This can reveal special cases such as cough-variant asthma and exercise-induced asthma. Additionally, the pediatrician will want to rule out other conditions such as viral bronchiolitis, cystic fibrosis (CF), bronchopulmonary dysplasia (scarring of the lungs in premature babies) and aspiration of a foreign body. Tests ordered may include spirometry in children >5 years old (blowing into a tube to test lung strength/capacity) and/or a sweat chloride test in children younger than 3 (to rule out CF).



The treatment for asthma depends on the severity. All asthma patients, regardless of severity, are placed on a short-acting beta agonist (SABA, an inhaler) on an as needed (prn) basis. The child’s response to the treatment will be reassessed at follow up in 2-6 weeks.

There are 4 levels of asthma, organized by their level of severity:

Intermittent (episodes < 3 d/week, no nighttime awakenings)
Mild persistent (episodes 3+ d/week)
Moderate Persistent (daily episodes)
Severe Persistent (episodes throughout the day with weekly nighttime awakenings)

The treatments for each are as follows:
Intermittent: SABA prn
Mild persistent: SABA + low-dose Inhaled corticosteroids (ICS)
Moderate Persistent: SABA + medium-dose ICS
Severe Persistent: SABA + high-dose ICS + long acting beta agonist (LABA)

An oral corticosteroid, such as prednisone, may be added in very severe cases where the inhaled medication isn’t working well. The reason for this is that if the airways are severely blocked, the inhaled medication will not be able to reach the tissues to be absorbed.

If a child experiencing an asthma exacerbation is not responding to his or her treatment, experiences a late night attack or has had a severe episode in the past, it’s important to bring them to the emergency room for monitoring. They may require endotracheal intubation, IV antibiotics and/or an IV theophylline drip.

The goals of the parent should include both prevention and preparedness:
  • Be sure to limit your child’s exposure to cigarette smoke, pollution, aerosol chemicals and any known triggers
  • Some studies have shown that breastfeeding reduces the risk of developing asthma, and others suggest that swimming helps improve lung function and reduce the severity of exacerbations



Reference
Asthma in Children. Dynamed Database. Updated May 7, 2014. Accessed July 1, 2014.