Exanthems Flashcards
VZV
Only humans.
Chickenpox as a primary infection.
Generalized pruritic vesicular rash all over body.
Low grade fever
Airborne transmission?
1)varicella 2)measles 3)TB 4) SARS
What are Complications of Varicella in immunocompromised patients?
- Thrombocytopenia
- encephalitis
- bacterial superinfection
- pneumonia
- hemorrhagic varicella
- acute cerebellar ataxia
Hand foot mouth disease
- Main cause: coxsackie A .
- Starts as fever and lymphadenopathy lasts 1-2 days ——> painful oval grey vesicles on : 1)palmar and plantar skin 2) buccal mucosa 3)hard palate 5) oral cavity 6) tongue.
- ccx: meningitis, myocarditis, pleurisy.
- d’s is self-limiting.
Molluscum Contagiosum
*highly contagious
*the pox virus.
*Its lesions often appear on the trunk, face, and extremities.
*described as 1-20 discrete, flesh coloured, dome
shaped umbilicated papules, with a diameter between 2-5 mm.
*The disease is self-limiting, resolving in 6 to12 months.
Erythema multiforme
- hypersensitivity reaction that happens in response to drugs, and infections, like HSV and mycoplasma pneumonia.
- it is frequently recurrent, and it lasts for 2-3 weeks.
- Erythema multiforme can develop into many forms, including erythema multiforme major, in which one mucous membrane is involved, Stevens Johnson syndrome, in which 2 mucous membranes are involved, or toxic epidermal necrolysis, in which more than 30% of the skin is involved.
What is Scarlet fever?
- caused by the erythrogenic toxin of group A strep (GAS), often with pharyngitis and rarely with pyoderma.
- erythematous sandpaper like rash with 1mm papules and red background, which covers the head and neck, the trunk, and limbs, and often desquamates.
- It is also characterized by slapped cheek appearance, and “Strawberry tongue”.
- Scarlet fever can cause rheumatic fever as a complication.
- It has the same treatment as GAS tonsillitis, which is penicillin or amoxicillin for 10 days, and this treatment will prevent rheumatic fever.
What are Measles ccc?
- highly contagious infectious disease caused by measles virus.
- It only infects humans
- it is rarely seen nowadays due to vaccination, and its incubation period is 10-12 days.
What’s the course of measles?
*starts with a prodrome that is characterized by 3 C’s: cough, coryza and conjunctivitis.
*These symptoms may be accompanied by fever, sore throat, and kolpik’s spots, which are
grey whitish spots on the buccal mucosa.
*Three days later, coalescing erythematous maculesand papules erupt in the hairline area, and spread cephalocaudally to the rest of the skin over a few days.
*Finally, it resolves in the same order it appeared, and it often desquamates.
*Measles is contagious 4 days before the rash to 4 days after the rash.
*Also, it is highly communicable. It spreads by direct contact with droplets or by airborne spread, in which the small particles, less than 5 microns, stay suspended in the air for a long period of time and
can infect anyone who comes in contact with them.
Complications of measles:
- acute encephalitis: permanent brain damage.
- subacute sclerosing pan encephalitis: rare degenerative CNS disease characterized by behavioural and intellectual deteriorations with seizures. This complication happens after 7-10 years of wild type measles infection, which is when a child gets infected by the virus naturally, not by the live attenuated vaccine
How do you diagnose measles and what’s the treatment?
Dx is by Serology look for measles IgM —-> acute infxn
Tt by Vit A .
What is Rubella?
- Rubella is a contagious disease caused by the rubella virus.
- only infects humans, it is included in the MMR vaccine, and its incubation period is 2-3 weeks.
What’s the course of Rubella
*Rubella is milder than measles.
*It starts with a subclinical or mild erythematous maculopapular rash, which starts on
the face and becomes generalized in 24 hours (unlike measles which takes a few days to
spread).
*It lasts for 3 days, that’s why it is called the 3 days measles.
What can Rubella cause?
- lymphadenopathy which usually precedes the rash.
- It characteristically involves the posterior auricular and suboccipital lymph nodes, and it could be generalized.
- Rubella can also cause conjunctivitis, palatal enanthem, polyarthralgia and polyarthritis in adolescents and adults,especially in females.
- Finally, it may cause serious complications like encephalitis and thrombocytopenia
For how long is rubella contagious?
Rubella is contagious a few days before the rash to 7 days after the rash, it is transmitted by
droplets, and it is seen more than measles because immunity for rubella wanes over time,
while immunity for measles is lifelong.
