Chickenpox passmed Flashcards
What causes Chickenpox and what is its relationship with Shingles?
Chickenpox is caused by primary infection with the varicella zoster virus. Shingles is a reactivation of this dormant virus in the dorsal root ganglion.
How is Chickenpox transmitted and what is its period of infectivity?
Chickenpox is highly infectious, spread via the respiratory route, and can be caught from someone with Shingles. Infectivity spans from 4 days before the rash appears until 5 days after the rash first appeared. The incubation period is 10-21 days.
Describe the clinical features of Chickenpox.
Clinical features include an initial fever, an itchy rash that starts on the head/trunk before spreading, becoming macular, then papular, and finally vesicular. Systemic upset is usually mild but tends to be more severe in older children and adults.
What are the key management strategies for Chickenpox?
Management is supportive and includes keeping cool, trimming nails, and using calamine lotion. School exclusion is advised until all lesions are dry and have crusted over, typically about 5 days after the rash onset. Immunocompromised patients and newborns with peripartum exposure should receive varicella zoster immunoglobulin (VZIG). If Chickenpox develops, IV aciclovir may be considered.
What are common and rare complications of Chickenpox?
Common complications include secondary bacterial infections of the lesions, possibly increased by NSAIDs, sometimes leading to cellulitis or necrotizing fasciitis. Rare complications include pneumonia, encephalitis (with possible cerebellar involvement), disseminated haemorrhagic Chickenpox, and very rarely, arthritis, nephritis, and pancreatitis.
What can a chest x-ray show in a case of healed varicella pneumonia?
A chest x-ray can show multiple tiny calcific miliary opacities throughout both lungs, which are uniform in size and dense, suggesting calcification. There are no focal lung parenchymal masses or cavitating lesions, characteristic of healed varicella pneumonia.
A 3-year-old girl is brought to the GP by a worried mother as her child has had a temperature for 72 hours and has now started to develop a rash on her torso and face. She describes the rash as forming in clusters.
The girl is not eating much but is drinking well and has no changes to her urinary or bowel movements. She has no significant medical history and her immunisations are up to date. No-one else in the family has been unwell recently but the mum does inform you that her daughter has recently started attending nursery and a few of the other children have had a similar rash.
On examination: temperature 38.8ºC, scabbed lesions on the left cheek, erythematous vesicles on the trunk.
Which of the following is the most appropriate management of this child?
Acyclovir
Ibuprofen
Flucloxacillin
Permethrin
Topical calamine lotion
Chickenpox has a prodrome of raised temperature before the rash begins on the torso and face
Important for meLess important
Chicken pox is a very infectious disease caused by varicella zoster virus and usually presents in childhood. There is a classic description of increased temperature for 2 days before developing clusters of erythematous vesicles predominantly affecting the torso and face. Children are infectious until all spots have scabbed over and should be kept home from nursery/school until this point. Management is through supportive measures, including calamine lotion to soothe the itch and paracetamol to control the fever.
Acyclovir is considered in immunodeficiency children who are at particular risk of developing complications such as pneumonia and meningitis.
Permethrin is the treatment for scabies which predominantly affects the web spaces of the fingers .
Flucloxacillin is advised for bacterial super infections on top of the chicken pox.
Ibuprofen should be avoided in chicken pox as there is an associated risk between use of NSAIDs and the development of necrotising fasciitis.
Jenna is an 18-year-old woman who was initially admitted with a fever and disseminated rash. She had not been previously vaccinated and was in contact with her 2-year-old cousin who had developed a fever and disseminated blisters and vesicles containing clear fluid. She began to have a fever and flu-like symptoms 2 weeks after seeing her cousin. Similar clear-fluid filled vesicles and blisters developed 3 days later and she was admitted for further observation.
After 3 days, she noticed that while most of her skin lesions are healing, one of the lesions on the thigh appears to be red and becoming hot to touch. An area of skin approximately 3x3cm was erythematous. The skin was marked and she was commenced on IV flucloxacillin. Over the coming 12 hours, the erythema around this lesion continued to spread. The pain around her leg increased in intensity, requiring morphine to take the edge off the pain. A blueish discolouration begins to develop around the rash.
Given the likely complication that has developed, what is the likely organism that has caused the complication?
Enterococcus faecalis
Clostridium perfringens
Staphylococcus aureus
Streptococcus bovis
β- haemolytic Group A Streptococcus
Chickenpox is a risk factor for invasive group A streptococcal soft tissue infections including necrotizing fasciitis
Important for meLess important
The development of fevers along with blisters and vesicles raises the suspicion that this is caused by chickenpox. Besides, this is more likely as she has been exposed to a child who has had similar symptoms. Chickenpox tends to be milder in children but can cause significant morbidity in adults.
The development of a rapidly evolving rash along with significant pains out of proportion to the rash seen should always raise alarm bells for necrotising fasciitis. Blueish discolouration of the skin is also suggestive of this. A surgical review should be sought immediately.
Invasive group A Streptococcus, a β-haemolytic Streptococcus, has been implicated as the cause for necrotizing fasciitis in patients with chickenpox. Extremely broad-spectrum antibiotics are initially used with the choices tailored to bacterial sensitivities when known.
Staphylococcus aureus can also result in necrotising fasciitis but is more commonly associated with patients who have other underlying medical conditions like diabetes.
Enterococcus faecalis does not tend to cause skin infections and are often associated with infections like endocarditis.
Streptococcus bovis is a gamma-haemolytic Streptococcus is most often associated with colorectal cancer associated endocarditis. It is not associated with skin infections.
Clostridium perfringens can cause necrotising fasciitis and presents as gas gangrene. This will present with crepitus under the skin which is not seen here.
A 4-year-old boy is brought in to see his General Practitioner by his mother with a 3-day history of a new rash. She says that the rash started on his torso and has now spread to his face, arms and legs. It is very itchy. He was unwell about 3-4 days before the onset of the rash with fever and coryzal symptoms.
On examination, he has a papular and vesicular rash across his torso, arms, face and legs. Some of the lesions are crusted over. There are 2 discrete blisters inside his mouth.
What is the most likely diagnosis?
Measles
Mumps
Roseola infantum
Rubella
Varicella zoster
Varicella zoster
Chickenpox has a prodrome of raised temperature before the rash begins on the torso and face
This child has chickenpox caused by the varicella-zoster virus. It commonly presents with a prodrome of coryzal symptoms before the onset of an intensely itchy rash. The rash follows the cycle of macular and papular lesions, which develop into vesicles that then crust over. Chickenpox is highly contagious and remains contagious until the last vesicle has crusted over.
Measles is also a viral infection that is secondary to the morbillivirus. It initially presents as a macular rash over the face. Children are often asymptomatic at this point. However, fever and coryza manifest whilst the rash spreads to the trunk and limbs. Koplik spots are white spots seen on the oral mucosa and are pathognomonic of measles. However, the rash described in this question is vesicular, making measles less likely.
Mumps is a viral illness that predominantly causes painful swelling of the parotid gland. It is typically preceded by a prodrome of non-specific symptoms of fever, general malaise and reduced appetite. It does not present with a rash making mumps the incorrect answer.
Roseola infantum is a viral infection commonly caused by human herpesvirus 6 or 7. Like chickenpox, it presents initially with fever followed by a rash. However, the rash seen in roseola is a pale pink, macular rash starting on the trunk, spreading to the face, arms and legs. The rash usually disappears after 48 hours and is not vesicular in nature, making varicella-zoster more likely to explain this boy’s symptoms.
Rubella (or German measles) is a viral infection that presents as a pale pink, macular rash on the face, torso, arms and legs. There is often prominent post-auricular and cervical lymphadenopathy, which is not mentioned in this question.
