What is Hirschsprung Disease?

Hirschsprung disease, also known as toxic megacolon, is a life threatening intestinal obstruction seen in children.

When a fetus is developing in the womb, each type of cell must successfully migrate to where it belongs and, once there, perform their assigned duties. In this case, the cells, neuroblasts, do not make it to their destination in the distal intestine or they arrive but forget to do their job.

The condition is relatively rare, only occurring in 1 in every 5,000 live births. It is four times more common in males, and the risk is increased in Down syndrome or if a family history is present.

One of the most telltale signs that an infant is suffering from Hirschsprung Disease is the failure of an infant to pass his or her first bowel movement, known as meconeum, within the first 24 hours of life. Other signs include abdominal distention, bilious (yellow bile) vomiting, jaundice and feeding intolerance.

Over 80% of cases occur in infants, but occasionally the condition is seen in older children. In these cases, the child may show signs of chronic constipation, abdominal distention, failure to thrive, fever, diarrhea, vomiting, explosive stools and/or overflow incontinence. These children typically have intermittent problems with having a proper bowel movement, often on laxatives to ease their pain.

The pediatrician will do a physical examination when he or she suspects intestinal obstruction, looking for abdominal distention and a tight anal sphincter. An abdominal x-ray will typically show a dilated section of bowel preceding the area of obstruction. If enterocolitis is ruled out, a contrast enema will be performed, though this test is only 70% sensitive (83% specific). The disease is confirmed by a pathologist following a suction rectal biopsy performed by a surgeon.

If the child is over 12 months old, this condition is very unlikely. Other conditions that may mimic this condition include functional constipation, medication side effects, lead poisoning, sepsis, intussusception, meconeum ileus, meckel diverticulum, hypothyroidism and intestinal malrotation, atresia or stenosis.

Studies have shown that these infants, especially if preterm, also have an increased risk for other congenital abnormalities, such as heart problems, so a doctor may decide to do a thorough workup.

The immediate treatment for Hirschsprung Disease is to “decompress” the bowel obstruction using a nasogastric tube, antibiotics and IV fluids. Once the child is stable, a surgeon will fix the abnormality by removing the affected area of bowel (Pull-through procedure). If the surgery is successful and infection (enterocolitis) is avoided, the prognosis is excellent (<1% mortality) and the child will live a normal life.

Reference

Hirschsprung Disease. DynaMed Database Accessed May 23, 2014, Updated January 24, 2013.

MERS Virus Not Considered a Major Threat to the U.S.

Middle East Respiratory Syndrome (MERS) virus has made its way into the United States after killing hundreds in the Middle East. The MERS virus, first isolated in 2012, is a coronavirus that spreads through respiratory droplets and causes a severe acute respiratory illness. Symptoms of infection include fever, cough and shortness of breath.

MERS, similar to the flu, can be quite dangerous to the elderly and those with compromised immune systems. Since it’s transmitted following close human-to-human contact, family members caring for their sick relatives can easily contract the virus. This seems to be why so many have been infected in the Middle East: Owing to poor living conditions and the lack of proper medical care, an estimated 30% of those infected have died.

Two confirmed cases have been reported in patients traveling from the Arabian Peninsula to the United States.

On May 2, MERS was confirmed in an Indiana hospital. The patient, a healthcare worker, had recently arrived from Saudi Arabia following layovers in London and Chicago. He was isolated and successfully treated. Shortly after, an Illinois resident whom had close contact with the infected patient before his hospitalization began exhibiting symptoms of infection. He tested positive for antibodies to the virus, suggesting he suffered a very mild illness before fully recovering.

On May 11, MERS was reported in an Orlando hospital. The patient, a healthcare worker, was traveling from Saudi Arabia and reported layovers in London, Boston and Atlanta. He felt unwell during the flight, so visited the Emergency Room after landing. He was successfully treated and is currently in good health.

The current strain of MERS virus is not a major threat to the United States. Still, communities of immuno-compromised citizens in close quarters are at risk. It is for this reason that hospitals and nursing homes across states like Florida are warning residents to stay aware of the warning signs.

• All viruses have the ability to mutate into a deadlier strain

• There is no evidence of sustained spreading in community settings

• If you’ve been in close contact with one of the individuals infected by MERS, call your healthcare professional and inform them promptly

• Always wear a protective mask (such as N95) when caring for a patient or relative with a cough and a fever

Reference

Middle East Respiratory Syndrome (MERS). Centers for Disease Control and Prevention. Accessed May 19, 2014. http://www.cdc.gov/coronavirus/mers/index.html

The Importance of Identifying a Morbilliform Rash

The term "morbilliform" is used to describe any skin finding that resembles the measles rash. The macular lesions are typically diffuse, red and 2-10 mm in diameter. They may become confluent (come together to form clusters) in some areas. 

It is very important for doctors to know the differential diagnosis for a morbilliform rash, since some of the conditions are deadly. The process occurring within the body leading up to the rash, known as the prodrome, will help the physician narrow the diagnosis.This prodrome can be learned by ascertaining a good history. 

Some notable causes of morbilliform rash are:

• Fifth Disease (erythema infectiosum/parvovirus B19/)
• Sixth disease (roseola infantum/herpesvirus 6)
• Streptococcal infection (Groups A, C)
• Echovirus
• Adenovirus
• Kawasaki Disease
• Rubella
• Measles
• Syphilis
• Meningeal Petechiae (or Waterhouse Friedrichsen Syndorme)
• Drug hypersensitivity Reaction (especially nevirapine, abacavir, phenytoin)

A study by Ramsay et al in 2002 evaluated the laboratory samples of 93 vaccinated children in England, and noted that the most common cause of the rash was a parvovirus B19 infection (17%). Group A strep was found in 15% of cases, and sixth disease (roseola infantum or herpesvirus 6) in 11%. None of the cases were caused by measles. The use of widespread vaccination has nearly eliminated the measles infection, making way for other viruses that cause similar rashes. It is paramount that physicians discern the cause of the findings.

Reference

Ramsay M, Reacher M, O'Flynn C, Buttery R, Hadden F, Cohen B, Knowles W, Wreghitt T, Brown D. Causes of morbilliform rash in a highly immunised English population. Arch Dis Child. 2002 Sep;87(3):202-6.

An Update on Cat Scratch Fever

Cat Scratch Disease, also known as Cat Scratch Fever, is found in more locations than just a Ted Nugent album. This disease, first isolated in 1992, is caused by a bacteria called Bartonella henselae and affects roughly 6.6 in every 100,000 children in the United States. It's mostly benign (harmless), and in some cases goes unnoticed. Every now and then, though, a mother may see this in her child and become concerned:

The bacteria is transmitted to cats, typically kittens, by fleas. When a child is scratched by the cat, or in some cases pets the cat and then rubs his or her eye, the bacteria enters their bloodstream.

In 2-3 weeks, the child will develop lymphadenopathy, or the enlargement of the lymph nodes. The most common location of the lymphadenopathy is in the neck (33% of cases), followed by the axilla (underarm, 27%) and inguinal (groin, 18%). The child will also develop the characteristic fever and may complain of a sore throat.

In children with weak immune systems (immunocompromised), the disease may become disseminated (spread throughout the body) and cause infection of the bone (osteomyelitis), brain (encephalitis, resulting in seizures) and eye (oculoglandular conjunctivitis). In children with heart valve problems, this disease may cause endocarditis (infection of heart valve). For this reason, the CDC recommends that these children and adults avoid playing with cats or kittens, especially those with fleas.

Since the disease goes away on its own, a doctor will only need to prescribe pain medication for the painful lymph nodes. There is limited evidence that antibiotics are helpful in treating Cat Scratch Fever, so put on an old record and let Ted do all of the work.

• Cases in adults are not uncommon. 80% of patients with cat-scratch disease are < 21 years old

• Cases of dogs, monkeys, porcupine quills and thorns have been reported

• The disease is not contagious. There are no reports of person-to-person transmission

• Laboratory diagnosis is difficult, since the organism can be difficult to see. Currently, polymerase chain reaction (PCR) or Warthin-Starry Stain is used

• Differential diagnosis of chronic lymphadenopathy includes L. venereum, mycobacteria, tularemia, brucellosis. mononucleosis, syphilis, toxoplasmosis, systemic fungal infections, sarcoidosis, lymphoma, connective tissue disease and kawasaki disease

Reference

Cat Scratch Disease. In DynaMed [database online]. EBSCO Information Services. 

Updated 2012 Oct 25. Accessed May 10, 2014.

Increasing Reports of Nicotine Poisoning in Children as E-cigarette Popularity Grows

As E-cigarettes gain popularity, the liquid refill bottles are mistakingly making their way into the hands of children. NEJM recently reported a case of a 10 month old boy that presented with vomiting, tachycardia, grunting respirations and truncal ataxia.

                                                              Photo courtesy of NEJM

Check out the original article here:
http://www.nejm.org/doi/full/10.1056/NEJMc1403843