Pediatrics Rotation Exam Course

Pediatric EOR: Infectious Disease (Pearls)

You have completed pediatric medicine EOR topics:

Atypical mycobacterial disease
Patient will present as a 3-year old with a firm inflamed swelling in the right submandibular area. Initial medical management with intravenous antibiotics was ineffective. Fine needle aspiration of the lesion reveals acid-fast bacilli on Ziehl-Neelsen staining. Subsequent biopsy demonstrates a granulomatous reaction in keeping with a Mycobacterial infection. Specific questioning reveals no family history of tuberculosis, abscesses or infections; there are no family pets, no exposure to birds and no unpasteurised milk consumption. An initial chest x-ray was normal and Mantoux testing was negative. Conventional anti-tuberculous therapy (Isoniazid, Rifampicin, and Pyrazinamide) is commenced. Definitive culture at 6 weeks isolates Mycobacterium avium intracellulare. The prescription is altered to include Clarithromycin.

Mycobacteria other than the tubercle bacillus sometimes infect humans

Atypical Mycobacterial infections in children are most frequently located in superior anterior cervical or in submandibular nodes (91%)

  • Children usually lack constitutional symptoms and present in 95% of cases with unilateral, subacute, progressive lymphadenopathy
  • The swelling is painless, firm and not erythematous
  • The majority of cases are reported in 1-5 year olds because there is increased tendency of these children to put objects contaminated by soil or stagnant water into their mouths. It may also be due to the relative poor immunity to Mycobacteria found in this age group

Mycobacterium avium complex (MAC) - HIV patients with CD4 < 50

  • Very common. Fever, diarrhea, weight loss, anemia.
  • Present in soil and water (not person to person)
  • Symptoms rarely occur in immunocompetent patients (increased in bronchiectasis). HIV patients when CD4 < 50
  • Diagnose with AFB and culture
  • Treat with clarithromycin + ethambutol for at least 12 months (+/- rifampin)
  • Prophylaxis for HIV patients with (azithromycin or clarithromycin) if CD4 < 50

Mycobacterium kansasii

  • Causes tuberculosis-like disease
  • Treat with Rifampin + ethambutol

Mycobacterium Marinum * REMEMBER MARINUM = AQUARIUM

  • Atypical mycobacterium found in fresh and saltwater - infection occurs after inoculation of the skin via abrasion or puncture in a patient with contact of an aquarium, saltwater, or marine animals.
  • Occupational hazard of aquarium handlers, marine workers, fishermen, and seafood handlers
  • Diagnose by culture.

Treat with tetracyclines, fluoroquinolones, macrolidessulfonamides for 4-6 weeks.

Epstein-Barr disease
ReelDx Rotation Room (mononucleosis)
Patient will present as → a 14-year-old boy with 3-days of sore throatfever, and generalized malaise. On exam, he has a temperature of 102.2 F (39.0 C), BP 96/50, and a diffuse exudate on both tonsils. He also is noted to have palpable splenomegaly, swollen painful lymph nodes, and mild hepatomegaly. Labs show leukocytosis of 12,000/mm3 with 50% neutrophils, 12% monocytes, and 38% lymphocytes. The rapid pharyngeal streptococcal screen is negative.

Epstein Barr mononucleosis is a viral illness characterized by a classic triad of fever + lymphadenopathy + pharyngitis

  • Diagnosed with positive heterophile antibody screen (Monospot) - may not appear early in the illness (positive within 4 weeks)
  • Atypical lymphocytes with enlarged nuclei and prominent nucleoli
  • A maculopapular rash develops in 80% of patients treated with ampicillin
  • Left upper quadrant pain secondary to splenomegaly and are at risk for splenic rupture - athletes should avoid vigorous sports for at least the first three to four weeks of the illness

Treatment is supportive

Erythema infectiosum (fifth disease)
ReelDx Rotation Room (erythema infectiosum)
Patient will present as → a 4-year-old who is brought to the office by his mother. The child has had a low-grade fever, headache, and sore throat for the past week. Four days ago, he suddenly developed a bright red rash on his cheeks, which during the past two days has spread to the trunk, arms, and legs. On physical examination, the child has erythema of the cheeks and a maculopapular rash with central clearing on the trunk spreading to the extremities. There are no other significant findings.

Parvovirus B19 - "slapped cheek" rash on face - lacy reticular rash on extremities, spares palms and soles

  • Resolves in 2-3 weeks

Treatment is supportive, anti-inflammatories

Hand-foot-and-mouth disease
ReelDx Rotation Room (hand-foot-mouth disease)
Patient will present as → a 2-year-old who is brought to the office by his mother. The child has had a low-grade fever, rash, and loss of appetite for the past two days. On physical exam, there are multiple 2-3-mm grey vesicular lesions on the bilateral palms and soles and several vesicles and ulcers on the oral mucosa. The physician assistant informs her parents that this disease typically resolves spontaneously and to keep the patient hydrated.

Children < 10 years old caused by coxsackievirus type A virus

Treatment is supportive, anti-inflammatories

Herpes simplex
ReelDx Rotation Room (herpes simplex)
Patient will present as → a 27-year-old female who complains of exquisite vulvar pain and blisters. She reports that she has experienced several similar episodes for the past 5 years. On examination, you find multiple, painful vesicles on her left labia minora. You recall that on a previous visit she had a positive chlamydia culture that was treated with azithromycin tablets.

The Herpes Virus: There are eight types of herpes viruses known to affect humans. They are called Herpes Human Viruses (HHV)

There are two types of Herpes Simplex viruses (HSV): HSV 1- Oral lesions, HSV 2 - Genital lesions

  1. HSV 1 - Oral lesions (tongue, lips, etc.)
  2. HSV 2 - Genital lesions (vulva, vagina, cervix, glans, prepuce, and penile shaft)
  3. HHV 3 - VZV (Varicella Zoster Virus commonly known as chickenpox or shingles)
  4. HHV 4 - EBV (Epstein Barr Virus is commonly known as infectious mononucleosis [mono or glandular fever])
  5. HHV 5 - CMV (Cytomegalovirus is the most common virus transmitted to a pregnant woman's unborn child)
  6. HHV 6 - Roseolovirus is more commonly known as the 6th disease or Roseola Infantum
  7. HHV 7 - Similar to HHV6 (not yet classified)
  8. HHV 8 - A type of rhadinovirus known as the Kaposi's sarcoma-associated herpesvirus (KSHV)
Herpes simplex virus type 1 Human herpesvirus 1 Gingivostomatitis, keratoconjunctivitis, cutaneous herpes, genital herpes, encephalitis, herpes labialis, esophagitis*, pneumonia*, hepatitis*
Herpes simplex virus type 2 Human herpesvirus 2 Genital herpes, cutaneous herpes, gingivostomatitis, neonatal herpes, aseptic meningitis, disseminated infection*, hepatitis*
Varicella-zoster virus Human herpesvirus 3 Chickenpox, herpes zoster, disseminated herpes zoster*
Epstein-Barr virus Human herpesvirus 4 Infectious mononucleosis, hepatitis, encephalitis, nasopharyngeal carcinoma, Hodgkin lymphoma, Burkitt lymphoma, lymphoproliferative syndromes*, oral hairy leukoplakia*
Cytomegalovirus Human herpesvirus 5 Infectious mononucleosis, hepatitis, congenital cytomegalic inclusion disease, hepatitis*, retinitis*, pneumonia*, colitis*
Human herpesvirus 6 Roseola infantum, otitis media with fever; encephalitis
Human herpesvirus 7 Roseola infantum
Kaposi sarcoma-associated herpesvirus Human herpesvirus 8 Not a known cause of acute illness but has a causative role in Kaposi sarcoma* and AIDS-related non-Hodgkin lymphomas that grow primarily in the pleural, pericardial, or abdominal cavities as lymphomatous effusions

Also linked with multicentric Castleman disease

*In immunocompromised hosts.

ReelDx Rotation Room (influenza)
Patient will present as → a  5-year-old with sudden onset of fever, chills, malaise, sore throat, headache, and coryza. The child is also complaining of myalgia, especially in her back and legs. On physical exam, the patient appears lethargic, has a temperature of 102.5 F, and palpable cervical lymph nodes. Breath sounds are distant with faint end-expiratory wheezes.

Influenza is a viral respiratory infection caused by orthomyxovirus resulting in fever, coryza, cough, headache, and malaise

  • Three strains exist: A, B, and C

Everyone > 6 mo should receive an annual influenza vaccine

  • Avoid vaccination: severe egg allergy, previous reaction, Guillain-Barré syndrome (GBS) within 6 weeks of previous vaccination, GBS in the past 6 weeks, <6 mo old. Avoid FluMist in pt with asthma

Dx: based primarily on patient history. A rapid antigen test can be performed in the clinic - the virus can be isolated from the throat or nasal mucosa

  • Rapid serology test are often available and are most accurate during the first few days of illness
  • Gold standard = RT-PCR or viral culture take 3-7 days to return
  • CXR in primary influenza pneumonia will show bilateral diffuse infiltrates
Sensitivities of rapid influenza diagnostic tests (RIDTs) are generally approximately 50-70%, but a range of 10-80% has been reported compared to viral culture or RT-PCR. Specificities of RIDTs are approximately 90-95% (range 85-100%). Thus false-negative results occur more commonly than false-positive results.

Treatment is symptomatic (for most) or with antivirals ⇒ ideally< 48 hours – Tamiflu (oseltamivir), inhaled Relenza (zanamivir), IV Rapivab (peramivir), and oral baloxavir (Xofluza)

  • Zanamivir and Oseltamivir both treat influenza A and B ⇒ (think Dr. “OZ” treats the flu)
  • Indications for antiviral treatment: hospitalized, outpatient with severe/progressive illness, an outpatient at high risk for complications (immunocompromised, pt with chronic medical conditions, >65 yo, pregnant women / 2 weeks postpartum)
Patient will present as → a 6-year-old child who is brought to the emergency room for a complaint of high fevers and a rash. His mother reports that she thought he had “just a cold” approximately one week ago—he had a mild fever, runny nose, conjunctivitis, and cough. Then he developed a rash that started on his face and gradually spread downward. The child has no significant past medical history, however, he was adopted from Russia at age 5, and his medical history prior to adoption is unknown. On examination, the child appears lethargic and has a temperature of 104.3. There is a mild injection of his conjunctiva and a generalized macular rash. White macules are noted on his buccal mucosa.

Measles is caused by a paramyxovirus and is transmitted by respiratory droplets, it has a 10-12 day incubation period. It progresses in three phases characterized by a prodrome, enanthem, and exanthem.

  • Prodrome: 1-3 days of a "the three C's" -coughcoryzaconjunctivitis, as well as fever
  • Enanthem (48 hours prior to exanthem) Koplik spots - irregularly-shaped, bright red spots often with a bluish-white central dot in the mouth
  • Exanthem (2-4 days after onset of fever): consists of a morbilliform, brick red erythematous, maculopapular, blanching rash, which classically begins on the face and spreads cephalocaudally and centrifugally to involve the neck, upper trunk, lower trunk, and extremities

DX: Clinical diagnosis of measles requires a history of fever of at least three days, with at least one of the three C's (cough, coryza, conjunctivitis)

  • Observation of Koplik's spots is also diagnostic of measles
  • Laboratory diagnosis of measles can be done with confirmation of positive measles IgM antibodies or isolation of measles virus RNA from respiratory specimens

TX: supportive with anti-inflammatories

  • Patients must be isolated for 1 week after onset of rash
  • Otitis media, pneumonia, diarrhea and encephalitis are known complications of rubeola.

Vaccination is highly effective: Administer a 2-dose series of MMR vaccine at ages 12 through 15 months and 4 through 6 years. The second dose may be administered before age 4 years, provided at least 4 weeks have elapsed since the first dose

Patient will present as → a 5-year-old male is brought to the clinic with acute onset of painful swollen parotid glands. His mother reports that he was fine last night, but awoke with the swelling this morning. He has no significant past medical history, but it is documented in his chart that his mother declined the recommended standard immunizations for children because of personal beliefs. On examination, the child appears well and has a temperature of 100.8 F. His right parotid gland is slightly more swollen than the left, but they both are markedly swollen and tender.

Mumps is a viral disease that is part of the paramyxovirus family. It presents with parotitis (painful parotid gland swelling), orchitis, or aseptic meningitis. It is transmitted through respiratory droplets and has an incubation period of 12-14 days

Patient will present as  a 21-year-old male with a 2-day history of malaise and low-grade fever; develops swelling in the lower face bilaterally with the right side more pronounced. He now has a red, swollen duct on the inside of his right lateral mouth. 

  • Prodrome of fevermalaise, and anorexia
  • Parotid enlargement(usually bilateral but not always synchronous) 24 h later
  • Swelling of submaxillary and submandibular glands
  • Orchitis(usually unilateral) with testicular enlargement two to three times normal size
  • Mumps is the most common cause of pancreatitis in children


  • During an outbreak, a diagnosis can be made by determining recent exposure and parotitis. Usually, the disease is diagnosed on clinical grounds, and no confirmatory laboratory testing is needed
  • If there is uncertainty about the diagnosis, a test of saliva or blood may be carried out; a newer diagnostic confirmation, using real-time nested (PCR) technology, has also been developed
  • As with any inflammation of the salivary glands, the serum level of the enzyme amylase is often elevated
  • CSF demonstrates increased lymphocytes and decreased glucose 


  • There is no available cure for mumps and treatment is supportive
  • Symptoms usually last for 7-10 days and patients are contagious for up to 9 days after onset
  • May need to provide scrotal support if painful or swollen testicle (as in case presentation)

MMR vaccine is given at 12-15 months then again at 4-6 years of age

Patient will present as → a 24-year-old with an increasing cough for 3 weeks.  The cough comes and goes sometimes lasting for 10 minutes and causing gasping inhalations.  The cough was preceded by a mild cough and cold 2 weeks ago.  She has completed all immunizations required to attend school and has no known drug allergies

Whooping cough (pertussis) is a highly contagious respiratory tract infection marked by a severe hacking cough followed by a high-pitched intake of breath that sounds like a whoop. Gram-negative bacteria Bordetella pertussis – high contagious

  • Consider in adults with cough >2 weeks, patients < 2 years old
    • Catarrhal stage: cold-like symptoms, poor feeding, and sleeping
    • Paroxysmal stage: high-pitched "inspiratory whoop"
    • Convalescent stage: residual cough (100 days)

Diagnosed by a nasopharyngeal swab of nasopharyngeal secretions – culture

Tx: macrolide (clarithromycin/azithromycin); supportive care with steroids / beta2 agonists

  • Vaccination: 5 doses – 2, 4, 6, 15-18 mo, 4-6yrs (DTap)
  • 11-18 yo = 1 dose Tdap
  • Expectant mothers should get Tdap during each pregnancy, usually at 27-36 weeks
Patient will present as → a 4-year-old is brought to the office by his mother because the daycare teachers noticed he is unusually restless at school. The mother also noticed that he has not been sleeping well lately and has started wetting the bed at night. The child is alert and cooperative but scratches his buttocks while you are interviewing. Cellophane tape applied to the perianal area reveals football-shaped ova under the microscope.

Pinworm infection, also known as enterobiasis vermicularis, is a human parasitic disease caused by the pinworm (a type of roundworm). The most common symptom is itching in the anal area. This can make sleeping difficult.

  • Perianal itching especially at night (eggs are laid at night)
  • Eggs cling to the fingers while itching and are transmitted to other people either directly or through food or surfaces
  • The eggs can thrive for 2-3 weeks on an inanimate object
  • Diagnosis is with a "scotch tape test' done in the early morning. Can see the eggs under microscopy

Treatment is with albendazole or mebendazole

ReelDx Rotation Room (roseola)
Patient will present as → a mother who brings her 8-month-old infant into the clinic with a complaint of high fevers for three days. She denies any other symptoms. On examination, the child appears very well and is playful with you despite having a temperature of 103.9 F. A complete physical examination and urinalysis are done and no source of the fever is found. You send her home with fever control measures and a follow-up appointment for the next day. The next day, the child is afebrile but has a generalized pink maculopapular rash

Roseola, also known as exanthema subitumroseola infantumrose rash of infantssixth diseasebaby measles. Caused by HHV 6 and 7

  • Typically the disease affects a child between six months and two years of age and begins with a sudden high fever (102-104°). This can cause, in rare cases, febrile convulsions due to the sudden rise in body temperature, but in many cases, the child appears normal
  • After a few days, the fever subsides, and just as the child appears to be recovering, a red rash appears
    • A blanching macular or maculopapular rash starting on the neck and trunk and spreading to the face and extremities. Occasionally the rash is vesicular. It is generally nonpruritic. The rash typically persists for one to two days
  • Only childhood viral exanthem that starts on the trunk -  spreading to the legs and neck

DX: clinical

TX: is supportive

  • Bed rest, fluids, and medications to reduce fever
Patient will present as → a mother who brings her 14-month-old daughter for evaluation of a rash. The mother describes the rash as beginning on the face and subsequently spreading to the rest of her body over 1 day. She also reports that her daughter has a mild fever and redness in her eyes. She has not been vaccinated per parents’ preferences. Temperature is 100°F (37.8°C). There is mild bilateral nonexudative conjunctivitispostauricular lymphadenopathy, and petechiae on the soft palate and uvulaPink maculopapules are found in the face, neck, trunk, and extremities. The rash disappears in three days.

  • "3-day rash"  pink light-red spotted maculopapular rash first appears on the face, spreads caudally to the trunk and extremities and becomes generalized within 24 hours (lasts 3 days)
  • Cephalocaudal spread of maculopapular rash, lymphadenopathy (posterior cervical, posterior auricular)
  • Although the distribution of the rubella rash is similar to that of rubeola, the spread is much more rapid, and the rash does not darken or coalesce
  • Teratogenic in 1'st trimester - congenital syndrome - deafness, cataracts, TTP, mental retardation

DX: Laboratory diagnosis of rubella is warranted when congenital rubella syndrome is suspected or when the diagnosis is sought for a condition compatible with the known complications of postnatal rubella, such as arthritis

  • Serologic assays, primarily enzyme immunoassays (EIA), are used most frequently
  • Rubella virus-specific IgM antibodies are present in people recently infected with the Rubella virus but these antibodies can persist for over a year and a positive test result needs to be interpreted with caution
  • The presence of these antibodies along with, or a short time after, the characteristic rash confirms the diagnosis

TX: consists of supportive care. No specific therapy for rubella infection is available. MMR vaccine (12-15mo, 4-6yr)

Varicella infection
ReelDx Rotation Room (HERE)
Patient with chickenpox will present as → a 7-year-old who is sent home from school because of a rash that began on her trunk and spread to her face and extremities. It began with small crops of tiny, red papules which progressed to teardrop vesicles on an erythematous base. These vesicles were noted to have grown cloudy in appearance, burst open, and have formed scabs. The lesions appear to be at different stages of healing.

Varicella (chickenpox): primary infections - clusters of vesicles on an erythematous base.

  • Dewdrops on a rose petal in different stages
  • It starts on the face and spreads down
  • Acutely causes chickenpox - becomes latent in the dorsal root ganglion
  • Symptomatic treatment may use acyclovir in special populations

Herpes zoster (shingles): varicella reactivation causing a maculopapular rash along one dermatome

  • Identified via tzanck smear with visualization of multinucleated giant cells
  • Zoster Ophthalmicus: shingles involving CCN V, dendritic lesions on slit lamp exam if keratoconjunctivitis is present
  • Zoster Oticus (Ramsay-Hunt Syndrome): facial nerve (CN VII) otalgia, lesions on the ear, auditory canal and TM, facial palsy auditory symptoms
  • Treat shingles with acyclovir, valacyclovir, and famciclovir - given within 72 hours to prevent post-herpetic neuralgia
  • Postherpetic Neuralgia: pain > 3 months, paresthesias or decreased sensation. Treat with gabapentin or TCA, topical lidocaine gel, and capsaicin
  • Herpes zoster vaccine is a live, attenuated virus vaccine - vaccination is recommended for immunocompetent adults > 60 years of age
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