Archive for November 2nd, 2008

Bullous papular urticaria

by Paul Rega, MD — published on November 2nd, 2008

Spot The Rash (http://www.idinchildren.com/200810/spot.asp) by M. Perlman, MD

A 9-year-old healthy boy presented to the clinic complaining of a three-day history of several moderately pruritic lesions on his lower legs. This was his third episode with similar lesions this summer.

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No one else in the family developed this rash, and he had not received any treatment. He spent much of his summer outdoors playing in the yard. The family had no pets, and there was no history of bed bugs. On physical exam, the dorsal aspect of the right foot has several grouped and linear 3 mm to 6 mm vesicles and one discrete 2 mm hyperpigmented excoriated papule extending to the right ankle.

Answer

The diagnosis is bullous papular urticaria or insect bite-induced hypersensitivity. Papular urticaria or insect bite-induced hypersensitivity is common in children. It is caused by a hypersensitivity reaction to arthropods such as mosquitoes, bed bugs, fleas or mites. One report cited that 5% of visits to a pediatric dermatology clinic during a four-week period were for papular urticaria. Papular urticaria is caused by both immediate (type 1) and delayed (type 4) hypersensitivity after a period of sensitization. Bullae typically develop in patients with more severe hypersensitivity.

Patients report moderately to intensely pruritic lesions that initially begin as urticarial papules and progress to vesicles or bullae in one to three days. Bites are commonly found on exposed areas like the extremities and face and often spare the trunk, axilla and groin. Caused by multiple bites, papules are often grouped or linear and may be referred to as representing the bug’s “breakfast, lunch and dinner.” Lesions tend to resolve in one to two weeks, but new lesions develop as patients are repeatedly bitten. Characteristically, old lesions may be reactivated when new bites occur and may last for several months. Scratching is common because of severe pruritus and often leads to erosions and risk for bacterial super-infection. Infected lesions may leave permanent scarring. Postinflammatory hyperpigmentation and hypopigmentation can persist for months to years, especially in individuals with dark skin.

Until the child is removed or protected from the arthropods or develops tolerance, the bites will continue to occur. This may take weeks to years. It is common to see bites in only some members of the family because of the varied hypersensitivity response within each individual and to the greater preference of particular arthropods for certain individuals. There appears to be a peak in the spring and summer concurrent with increased exposure to insects; however, patients may present throughout the year in warmer climates and from exposure to indoor fleas or bed bugs.

It may be difficult to ascertain the source of the exposure, thereby making it challenging to convince parents that the eruption is caused by bites. Locating the source of the bites often requires detective work, and families may be insulted when questioned about insects or fleas in the home. If the family does not have pets, the offending arthropod may be from other pets with which the patient comes into contact; including those belonging to neighbors, other family members, a school or a day care facility. Explaining to the family that the child is “highly allergic” to insect bites often makes the family more likely to accept the diagnosis.

Skin biopsy may help confirm the diagnosis and shows spongiosis (epidermal intercellular edema), subepidermal edema and a superficial and deep perivascular and interstitial infiltrate mixed with lymphocytes and eosinophils. The differential diagnosis includes acute and chronic urticaria, atopic dermatitis, contact allergic dermatitis, drug-hypersensitivity reaction, pityriasis lichenoides et varioliformis acuta, papular acrodermatitis of childhood, neurogenic excoriations, linear IgA bullous dermatosis, lymphomatoid papulosis and, rarely, lymphoma.

Prevention for mosquito exposure includes avoiding exposure and using insect repellents such as DEET (in concentrations of less than 30%) or picaridin and wearing protective clothing when outside. Prevention and treatment for fleas include bathing pets regularly and treating them with flea collars and medication. Bedding should be washed frequently and the home vacuumed regularly. Treatment of bed bugs includes locating the source and cleaning sheets and mattress pads every two to four weeks as well as spraying the home and car with pesticides. If there is a significant bed bug infestation, old mattresses and couches may need to be discarded. Professional exterminators may be necessary to eradicate fleas and bed bugs.

Pruritus can be managed with mid; to high-potency topical steroids to individual lesions and with oral antihistamines. Topical preparations with menthol, camphor or praxomine also may be helpful. However, because of the chronic nature of the lesions, prevention and patience may be the best option until tolerance develops. Papular urticaria can be frustrating for patients and parents, especially if the families have already had an extensive evaluation or have been referred to a subspecialty clinic such as allergy or dermatology. The clinician’s ability to recognize this common disorder and explain the natural history to families may help with acceptance of the diagnosis and appropriate treatment.

For more information:

  • Marissa Perman is at Cincinnati Children’s Hospital Medical Center.
  • Hernandez RG, Cohen BA. Insect bite-induced hypersensitivity and the SCRATCH principles: a new approach to papular urticaria. Pediatrics. 2006;118:e189-196.
  • Howard R, Frieden IJ. Papular urticaria in children. Pediatr Dermatol. 1996;13:246-249.
  • Paller AS, Mancini AJ. Hurwitz Clinical Pediatric Dermatology: A Textbook of Skin Disorders of Childhood and Adolescence. Philadelphia: Elsevier; 2006:461-463.
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categories: Emergency Medicine

OMNI Postings of 11/2/08

by Paul Rega, MD — published on November 2nd, 2008
1)  So you want a career in EMS?  Not in Britain, you don’t.  They average about 1000 assaults per week there.  Most of the attacks are due to arguments as to who is the best secret agent:  James Bond or Austin Powers.
2)  This abstract in Pediatrics looked at trends in traumatic brain injuries in kids.  From 1991 to 2005, the estimated annual incidence rate of pediatric hospitalizations associated with traumatic brain injury decreased 39%, from 119.4 to 72.7 hospitalizations per 100 000. Fatal hospitalization rates decreased from 3.5 deaths per 100 000 in 1991–1993 to 2.8 deaths per 100 000 in 2003–2005.
3)  We always worry about patients who get a finger-tip injury related to an air-gun injection.  The pressure can send debris and trauma and cause massive complications along the entire appendage.  Here is a case of pneumomediastinum related to just such an injury.
4)  Here is a brief case history and a photo on a kid with scabies. (Scratch, scratch)  There is also a brief discussion on the disease and what to do about it.  (Scratch, scratch)  Permethrin is the most commonly used in the United States, and it is recommended as a first-line therapy by the Centers for Disease Control and Prevention (CDC). It’s applied from chin to toes and for a period of 10-12 hours, after which it should be washed off. (Scratch, scratch) The treatment is repeated in 1 week. Permethrin is the recommended drug of choice for infants (age >2 mo), children, and pregnant (Class B) and nursing mothers. (Scratch, scratch)
5)  China is also one of the world’s largest exporters of food and food ingredients, including meats, seafood, beverages and vitamins.  If eggs, milk and animal feed are tainted with melamine, there is the specter of an even wider array of foods that could come under scrutiny, including pork, chicken, bread, cakes, seafood and candy.  Anybody care for another order of Moo Shu Gai Croak?  Or how about  Poo Shi Uppee Daysi?
Paul R.
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categories: Emergency Medicine

Britain: Violence Against Medics

by Paul Rega, MD — published on November 2nd, 2008

BBC, 11/2/08 (http://news.bbc.co.uk/2/hi/uk_news/7703334.stm):  Ambulance services across the UK hold records of more than 8,500 households who have a history of violence against paramedics, the BBC has learned.

Staff called to emergencies at these addresses are advised to wait for police before entering the premises.

The Patients Association says records must be “absolutely accurate” or “patient safety may be in danger”.

Unison is calling for the system to be reviewed, saying there are “serious questions” about how it works.

The union says paramedics are faced with a moral dilemma, forced to make a difficult choice between their own safety and that of their patients.

Karen Jennings, from Unison, said: “I think there are serious questions to ask about whether ambulance crews should sit outside if somebody inside is having a heart attack.

“Having said that, if that household has a history of attacking people when they go in, then it doesn’t do anybody any good if they were just to rush in and put themselves at risk.”

There are an estimated 1,000 attacks a week on health workers and members of the emergency services.

Sexual attacks

Fear of violence has led to all paramedics in London being offered stab-proof vests to wear on duty, and increasingly, there are calls to hand them out to staff nationally.

Another way of responding to the problem has been for ambulance services to keep a record of addresses where there have been abuse, threats or attacks.

BBC Radio 5Live’s Donal McIntyre programme has obtained a region-by-region breakdown of those records.

The West of England division, which covers Bristol, Swindon and Gloucester, currently has 312 addresses flagged as “at-risk”. About half were reported for physical violence and 58 for sexual attacks.

In London, the number is 1,930, but the service did not specify the reasons why properties were included.

The North West has the most flagged households – 3,071 – but a spokesman pointed out that they made up just 0.10% of all residential addresses.

Andy Price, a paramedic in the West Midlands, told the programme he was assaulted when responding to a call for an arm injury.

“When we arrived on the scene it very quickly became apparent that the reason for which we had been called was perhaps erroneous,” he said.

“There was a number of people there – they had all been drinking quite heavily. My colleague, while attempting to calm the situation, was punched in the face.

“I was later punched in the face myself. I required several days off work.”

Another paramedic who has more than 20 years service at the North East Ambulance NHS Trust believes the problem has got worse recently.

“Even 10 years ago people wouldn’t dream of verbally abusing you – now with drinking and drug problems it’s much more common,” he said.

Behaviour

The Patients Association says flaws in the system could put patients at risk.

Spokeswoman Vanessa Bourne said: “A record like this has to be absolutely accurate and up to date. If they are not, patient safety and lives may be in danger.

“There are many reasons why a patient’s behaviour puts them on the register, but they may be the patients most in need of care.”

The recent Emergency Workers (Obstruction) Act 2006 makes it an offence to obstruct or hinder persons who provide emergency services.

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categories: Emergency Medicine