Module 9 Part 2 Patho Mononucleosis Flashcards
Question
Answer
What is infectious mononucleosis (IM)?
IM is an acute, self-limiting clinical syndrome characterized by B lymphocyte infection.
What is the most common cause of IM?
Epstein-Barr virus (EBV) is the most common cause of IM, accounting for approximately 85% of cases.
Name other viruses that can cause symptoms resembling IM.
Other viruses include cytomegalovirus (CMV), adenovirus, HIV, hepatitis A, influenza A and B, and rubella.
Which bacteria can cause symptoms similar to IM?
Bacteria like Toxoplasma gondii, Corynebacterium diphtheriae, and Coxiella burnetii can cause similar symptoms.
What are the classic symptoms of IM?
The classic symptoms include pharyngitis (sore throat), lymphadenopathy (swollen lymph nodes), and fever.
When do most people become infected with EBV, and what happens during early infections?
Most people are infected with EBV during childhood. Early infections are usually asymptomatic and provide immunity to EBV.
When does symptomatic IM typically occur, and who does it affect?
Symptomatic IM usually occurs when the first EBV infection happens in adolescence or later. It often affects young adults between ages 15 and 35.
When is the peak incidence of IM, and what is the overall incidence rate in the affected age group?
The peak incidence occurs between ages 1-6 and 14-20 years. The overall incidence rate is about 2 to 3 cases per 1,000 persons per year.
Who is particularly susceptible to EBV infections?
Children from low socioeconomic environments are particularly susceptible to EBV infections.
Is IM common in individuals older than age 40, and what might cause it in older individuals?
IM is uncommon in individuals over age 40. If it occurs, it is commonly caused by cytomegalovirus (CMV).
How is Epstein-Barr virus (EBV) typically transmitted?
EBV is usually transmitted through saliva from close personal contact, such as kissing, which is why it’s sometimes called the “kissing disease.”
Besides saliva, where else can EBV be found in bodily secretions?
EBV may also be present in genital, rectal, and respiratory secretions, as well as in blood.
How does EBV infection begin in the body?
EBV infection starts with the widespread invasion of B cells, which have specific receptors for EBV.
In which parts of the body does the initial EBV infection occur?
The initial EBV infection takes place in the mouth and throat, particularly in the oropharynx, nasopharynx, and salivary epithelial cells.
Where does EBV infection spread in the body after the initial site of infection?
EBV later spreads to lymphoid tissues and B cells in the body.
What happens in the immune response against EBV in immunocompetent individuals?
In immunocompetent individuals, unaffected B cells produce antibodies (immunoglobulins IgG, IgA, IgM) against the virus. There’s also a significant proliferation of T-cytotoxic cells (CD8) directed against EBV-infected cells.
What is responsible for the cellular proliferation in lymphoid tissues (e.g., lymph nodes, spleen, tonsils) during an EBV infection?
The immune response against EBV-infected cells plays a significant role in cellular proliferation within lymphoid tissues.
How does EBV infection spread throughout the body once it enters the bloodstream?
Once EBV enters the bloodstream, the infection spreads throughout the body.
What symptoms are associated with the inflammation at the site of the first viral entry in the mouth and throat during an EBV infection?
Inflammation at the site of first viral entry (the mouth and throat) can cause sore throat and fever.
What is the typical incubation period for Infectious Mononucleosis (IM)?
The incubation period for IM is usually about 30 to 50 days.
What are some early symptoms of IM that can appear during the first 3 to 5 days after infection?
Early symptoms can include headache, malaise, joint pain, and fatigue. However, some individuals may not experience any symptoms.
What are the classic symptoms individuals commonly present with at the time of IM diagnosis?
At the time of diagnosis, individuals with IM typically have fever, sore throat (pharyngitis), cervical lymph node enlargement, and fatigue.
How does pharyngitis typically appear in IM?
Pharyngitis in IM is usually diffuse with a whitish or greyish-green, thick exudate. It can be painful, leading individuals to seek treatment.
What can be observed as IM progresses?
As IM progresses, individuals may develop generalized lymphadenopathy, an enlarged spleen, and the appearance of atypical activated T lymphocytes in the blood.
Is IM a self-limiting condition, and if so, how long does recovery typically take?
Yes, IM is usually self-limiting, and recovery occurs within a few weeks.
What is a common lingering symptom after the resolution of IM?
Fatigue may persist for 1 to 2 months after the resolution of the infection.
How common are severe clinical complications in Infectious Mononucleosis (IM)?
Severe clinical complications are rare in IM.
What complications may develop with the progression of IM?
As IM progresses, it can lead to general lymph node enlargement and splenomegaly (enlarged spleen).
Why is it challenging to detect splenomegaly in IM through physical examination?
Splenomegaly is observed radiologically in all cases, but it may not be clinically evident due to the difficulty of physical examination.
What is splenic rupture, and how common is it as a complication of IM?
Splenic rupture is a rare but serious complication of IM. It primarily affects men under 25 years old and occurs between days 4 and 21 after symptom onset. It is the most common cause of death related to IM.
Besides splenic rupture, what are other potential causes of fatalities related to IM?
Other causes of fatalities in IM include hepatic failure, extensive bacterial infection, and viral myocarditis.
What are some organ systems that can rarely be involved in IM, leading to characteristic manifestations?
Other organ systems may include manifestations such as hepatitis with jaundice and anemia, encephalitis, meningitis, Guillain-Barré syndrome, Bell’s palsy, and eye manifestations.
What is Reye syndrome, and when does it develop in the context of EBV infection?
Reye syndrome can develop in children with EBV infection.
Who is more likely to experience pulmonary and respiratory failure in IM, and under what circumstances?
Pulmonary and respiratory failure is more likely to occur in immunocompromised individuals.
What percentage of adults older than 40 years who have not been previously infected with EBV are susceptible to IM later in life?
Approximately 3 to 10% of adults older than 40 who have not been previously infected with EBV remain susceptible to IM later in life.
What makes the diagnosis of IM more challenging in these individuals?
In individuals who have not been previously infected with EBV and develop IM later in life, the classic symptoms are not generally present, making diagnosis more difficult.
What is the basis for diagnosing Infectious Mononucleosis (IM)?
Diagnosis of IM is based on specific findings in blood tests.
What specific criteria are used in diagnosing IM based on blood tests?
Diagnostic criteria include an increase in the number of lymphocytes, with at least 50% of the cells being lymphocytes and at least 10% being atypical lymphocytes in the blood.
What is the monospot test, and why is it commonly used for diagnosing IM?
The monospot test is a positive heterophile antibody reaction, and it is commonly used for diagnosing IM.
How does the monospot test detect IM?
The monospot test detects heterophilic antibodies, which are a group of IgM antibodies against nonhuman red blood cells (e.g., horse, sheep).
What are the limitations of the monospot test in diagnosing IM?
The monospot test may lead to false-positive results (5 to 15%) because other infections, like CMV, adenovirus, and toxoplasmosis, can also produce similar heterophilic antibodies.
How do heterophilic antibodies in the blood change as IM progresses?
Heterophilic antibodies in the blood increase as the condition progresses.
Are heterophilic antibodies produced in all individuals with IM, including children?
No, some individuals and children younger than 4 years old do not produce these antibodies.
Besides the monospot test, how can the diagnosis of EBV infection be enhanced?
Newer viral-specific tests that detect EBV-specific antibodies can enhance the diagnosis of EBV infection.
What is the primary approach to treating Infectious Mononucleosis (IM)?
Treatment for IM is primarily supportive and aims to relieve symptoms.
What are the key components of supportive treatment for IM?
Supportive treatment includes rest and symptom relief using analgesics and antipyretics.
Why is aspirin avoided in the treatment of IM, especially in children?
Aspirin is avoided because it is associated with Reye syndrome, a severe condition.
How is streptococcal pharyngitis, which occurs in a significant number of IM cases, treated?
Streptococcal pharyngitis is treated with penicillin or erythromycin.
Why is the use of ampicillin or amoxicillin avoided in IM treatment?
These antibiotics are avoided because they can cause a rash.
Besides medication, what lifestyle recommendations are made for individuals with IM?
Patients are advised to get bed rest, avoid strenuous activities, and refrain from contact sports.
When are steroids considered in the treatment of IM?
Steroids are considered when severe complications like impending airway obstruction or other organ involvement (e.g., central nervous system manifestations, thrombocytopenic purpura, myocarditis, pericarditis) are present.
What is the role of Acyclovir in IM treatment, and when is it used?
Acyclovir has been used in immunocompromised individuals with IM, but it is not considered standard therapy.
What is the standard treatment for splenic rupture, a rare complication of IM?
The standard treatment for splenic rupture is the removal of the spleen.
. What emerging approach to splenic rupture treatment is suggested by current research?
Current research suggests that repairing the spleen may be a better option to avoid overwhelmingpostsplenectomyinfection.
