Exanthems and Viral Infections Quiz
23 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following is caused by the measles morbillivirus?

  • Rubella
  • Scarlet fever
  • Erythema infectiosum
  • Measles (correct)

    • What characterizes an exanthem?

  • Rash confined to the extremities
  • Itchy, raised hives on the skin
  • Localized rash with scales
  • Symmetric and widespread rash without scales (correct)

    • Which of the following is a known aetiological agent of rubella?

  • Rubella virus (correct)
  • Coxsackievirus
  • Parvovirus B19
  • Streptococcus pyrogens

    • Which condition is primarily associated with Staphylococcus infections?

    <p>Staphylococcal toxic shock syndrome</p> Signup and view all the answers

    What type of rash is typically characterized by raised spots?

    <p>Papules</p> Signup and view all the answers

    Which vaccine is available for preventing rubella?

    <p>Measles, Mumps, and Rubella (MMR) vaccine</p> Signup and view all the answers

    Which of the following is NOT a common characteristic of viral exanthems?

    <p>More prevalent in adults</p> Signup and view all the answers

    Chickenpox is primarily caused by which virus?

    <p>Varicella zoster virus</p> Signup and view all the answers

    What is the causative agent of scrub typhus?

    <p>Orientia tsutsugamushi</p> Signup and view all the answers

    What is one of the common early symptoms of scrub typhus?

    <p>Fever and chills</p> Signup and view all the answers

    What type of sample is usually used for serological diagnosis of scrub typhus?

    <p>Paired samples of Ig M and Ig G</p> Signup and view all the answers

    Which of the following is not a preventive measure for scrub typhus?

    <p>Vaccination against typhus</p> Signup and view all the answers

    Which treatment is commonly used for scrub typhus?

    <p>Doxycycline</p> Signup and view all the answers

    What is the incubation period for chickenpox?

    <p>10-21 days</p> Signup and view all the answers

    Which virus is responsible for measles?

    <p>Paramyxovirus</p> Signup and view all the answers

    Which of the following is NOT a complication associated with measles?

    <p>Hemorrhagic rash</p> Signup and view all the answers

    What type of rash is commonly associated with chickenpox?

    <p>Vesicular rash</p> Signup and view all the answers

    What is a notable feature of the rubella rash?

    <p>It is a fine, pink rash that appears in a specific sequence</p> Signup and view all the answers

    Which of the following best describes the virulence factor of the Group A Streptococci that helps resist phagocytosis?

    <p>M protein</p> Signup and view all the answers

    What is the primary method of laboratory diagnosis for Group A streptococcal infections?

    <p>Blood cultures from all suspected cases</p> Signup and view all the answers

    What initial symptoms are commonly associated with streptococcal toxic shock syndrome (STSS)?

    <p>Fever and severe pain</p> Signup and view all the answers

    Which chemoprophylaxis is first-line for meningococcal sepsis?

    <p>Ciprofloxacin</p> Signup and view all the answers

    Which is the characteristic rash of Neisseria meningitidis infection?

    <p>Maculopapular, nonpluratic lesions</p> Signup and view all the answers

    Study Notes

    Exanthems

    • Exanthem is a widespread rash, symmetric, and red with macules or papules.
    • Exanthems are caused by viral or bacterial infections.
    • Exanthems can be caused by drugs, toxins, or autoimmune diseases.

    Viral Exanthems

    • Very infectious.
    • More common in childhood.
    • Can cause outbreaks/ epidemics.
    • High morbidity.
    • Adults get more severe disease.

    Measles (Rubeola)

    • Caused by the measles morbillivirus.
    • Incubation period 10-21 days.
    • Prodrome of runny nose, fever, cough.
    • Koplik spots: tiny spots in oral mucosa red with blue-white centers.
    • Complications like acute otitis media, viral pneumonia, myocarditis, pericarditis, encephalitis (0.1% of cases).

    German Measles (Rubella)

    • Caused by the rubella virus.
    • Symptoms are generally low-grade fever, enlarged lymph nodes, and an itchy rash.
    • Rash appears fine and pink on the face, trunk, arms, and legs.
    • Rubella is less infectious and severe than measles.
    • Lacks post-measles staining.

    Erythema Infectiosum

    • Caused by parvovirus B19.
    • Incubation period 4-14 days.
    • Affects preschool and school-age children.
    • Prodrome: 1-3 days or absent.
    • "Slapped cheek" appearance with circumoral pallor.
    • Lacy reticular pattern or fading rash.
    • Contagious up to the presence of rash.
    • Spread via respiratory route.

    Chickenpox (Varicella)

    • Caused by a herpes virus.
    • Itchy, fluid-filled blisters that eventually scab over.
    • Starts on the chest, back, and face, then spreads to the rest of the body.
    • Palms and soles are spared.
    • Successive crops of blisters.
    • Incubation period 10-21 days.
    • Fever with the onset of the rash.

    Group A Streptococci

    • Erythrogenic toxins cause rash in scarlet fever.
    • Haemolysins:
      • Streptolysin O (Oxygen labile - antigenic).
      • Streptolysin S (Oxygen stable - haemolysis).
    • DNAses: hydrolyze nucleic acid.
    • C5a peptidase: inactivates human C5a.
    • Pyrogenic exotoxins: SPE-A, SPE-B, SPE-C.
    • Streptokinase: spreads infection.
    • Hyaluronidase: degrades hyaluronic acid.
    • M protein: resists phagocytosis by PMNL.
    • F protein: binds to host fibronectin and mediates internalization of bacteria into host cells.
    • Hyaluronic acid capsule: antiphagocytic.

    Meningococcal Sepsis

    • Caused by Neisseria meningitidis.
    • Gram-negative diplococci.
    • Common serotypes: A, B, C, W135, Y.
    • Rapidly fatal.
    • Rash: maculopapular, non-purulent erythematous lesions on extremities sparing the body.
    • Petechial rash in 75% of cases.

    Rickettsial Infections

    • Rocky Mountain spotted fever: R. rickettsii, spread by ticks.
    • Rickettsialpox: R. akari, spread by mites on wild rodents.
    • Scrub typhus: Orientia tsutsugamushi, spread by larval mites.
    • Epidemic typhus: R. prowazekii, spread by lice.
    • Murine endemic typhus: R. typhi, spread by fleas.

    Typhus

    • Scrub typhus is caused by Orientia tsutsugamushi.
    • Spread to people through bites of infected larval mites.
    • Symptoms: fever, headache, body aches, rash.
    • Common in Southeast Asia, Indonesia, China, Japan, India, and northern Australia.
    • Treated with doxycycline.

    Laboratory Diagnosis

    • Rash may give a clinical diagnosis.
    • Viruses can be isolated but are no longer commonly done.
    • Serology: paired samples of IgM and IgG.
    • Bacterial culture: blood cultures, throat swabs, vesicular fluid, CSF, pleural fluid, EDTA blood for PCR.

    Treatment

    • Symptomatic: hydration, antipyretics, antihistamines for itching.
    • Rest, nutrition, isolation until infectivity ends.
    • Chickenpox: aciclovir.

    Prevention

    • Vaccination available for varicella, measles, rubella, and meningococci.
    • Typhus: no vaccine available.
    • Due to long incubation periods, post-exposure prophylaxis with vaccination possible for measles and chickenpox.
    • Know your local EPI schedule.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Fever with Rash PDF

    Description

    Test your knowledge on exanthems, including their causes, characteristics, and specific types like measles and rubella. This quiz covers the epidemiology, symptoms, and complications associated with these viral infections. Ideal for students studying infectious diseases.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser