You are informed by the infectious diseases director at your hospital that a patient admitted 2 days ago via the ED has a confirmed case of measles.
Which ONE of the following is INCORRECT?
Answer: D: Measles is a highly contagious endemic myxovirus infection that is now seen in sporadic cases due to widespread immunisation. An incubation period of 10 days followed by a 3-day prodrome of upper respiratory symptoms progresses to malaise, fever, conjunctivitis, cough, coryza and systemic toxicity. The rash begins behind the ears and in the hairline and spreads to down the body and limbs; it is blanching, erythematous, maculopapular and lasts about 7 days. Koplik spots, 1 mm white spots on the buccal mucosa, are pathognomonic.
Treatment is supportive and infection control to prevent spread of disease is vital. If the diagnosis is suspected patients should be isolated in a negative pressure room with droplet precautions (masks) taken at all times. Unimmunised contacts, including staff, should be vaccinated within 72 hours; in addition, unimmunised exposed contacts who are at high risk of complications from the disease (infants < 1 year, pregnant women, immunosuppressed persons) should also receive immunoglobulin.
References:
A 30-year-old man presents to the ED with fever, malaise and painful hands. He has no history of trauma or prior joint disease, takes no medications and has no allergies. On examination he is systemically well and his observations are normal (temp 37.5°C). He has tenosynovitis and arthritis of the right wrist and hand with no other arthritis, and he also has several small pustules over the hands and wrists.
What is the MOST likely diagnosis in this patient?
Answer: B: DGI affects up to 3% of patients with Neisseria gonorrhoeae. Two clinical pictures exist (although there may be overlap between them):
Tenosynovitis may affect many tendons simultaneously, and is uncommon in other infectious forms of arthritis. The rash associated with DGI usually develops on the extensor surfaces of the wrists, palm and hands, as well as the dorsal aspects of the ankles and feet. Diagnosis is made on clinical findings plus skin, synovial, blood and cervical/ urethral cultures, although these may be negative. Treatment involves parenteral antibiotics (ceftriaxone due to penicillin and quinolone resistance) plus azithromycin or doxycycline to cover Chlamydia; asymptomatic infected partners should also be treated.
Lyme disease is caused by the bacterium Borrelia burgdorferi and is transmitted to humans by ticks. There is little evidence that it occurs in Australia, however, it cannot be ruled out. Typical symptoms include fever, headache, fatigue, myalgia, arthralgia and a characteristic skin rash called erythema migrans (pink or red rash that starts as a small red spot and gradually spreads in a much larger circle with a characteristic bullseye appearance). The later stages involve neurological and cardiac consequences.
Reactive arthritis (formerly known as Reiter’s syndrome) is characterised by an acute, asymmetric oligoarthritis occurring 2–6 weeks after an infectious illness (post venereal or post dysentery). Joint involvement typically involves the lower extremities. The classic triad of urethritis, conjunctivitis and arthritis are seldom seen. Additionally, there may be a psoriasis-like skin eruption, but petechiae, macules, papules or maculopapules do not occur.
Common manifestations of acute HIV infection (seroconversion illness) are fever, an erythmatous maculopapular rash, myalgia and arthralgia, headache and cervical lymphadenopathy. The rash is usually more generalised and joint effusions uncommon; DGI and acute HIV infection can coexist.
The differential for DGI includes:
A patient presents with a painful thigh; there is no history of trauma, heavy exercise or prior skin lesion. On examination he is tachycardic and has a lowgrade fever, but there are no clinical signs in the affected leg. He is admitted for observation and is subsequently diagnosed with necrotising fasciitis.
Which ONE of the following regarding necrotizing fasciitis is INCORRECT?
Answer: D: Necrotising soft-tissue infections form a spectrum of disease differentiated by the depth of infection: adipositis, fasciitis and myositis (superficial to deep). They are most commonly a polymicrobial infection (caused by aerobes and anaerobes) but Clostridium species and group A Streptococcus can cause single-organism infections. Clostridium infections are now an uncommon cause due to improvements in hygiene and sanitation.
Clinical features of all the necrotising soft tissue infections include pain out of proportion to the clinical findings, mild erythema and oedema, brawny induration, and late in the course, possible crepitus due to gas formation. Gas formation may be due to multiple organisms, including Clostridia, E. coli and others. The patient is usually unwell but if presents early in the illness may have few systemic features. The mortality is high due to systemic toxicity, and early detection and immediate treatment are required. Management involves aggressive resuscitation and supportive care, broad-spectrum antibiotics (e.g. empiric carbapenem plus clindamycin, or benzylpenicillin plus clindamycin), surgical debridement including amputation if required, plus possible hyperbaric oxygen therapy after surgery.
Parents bring a 6-month-old infant to the ED with a history of poor feeding and a fever. On examination there are ulcerated lesions throughout the mouth and on the lips; the remainder of the examination is unremarkable.
Which ONE of the following is CORRECT?
Answer: B: The clinical picture described is that of primary herpes gingivostomatitis, which may present in infancy or later in childhood or adulthood. Typically, vesicular lesions affect the oral cavity; these become ulcerated and then often spread to involve the lips, cheeks and chin. In young children, the presenting symptom may be oral pain or refusal to feed. The causative organism is HSV-1; HSV-2 causes neonatal herpes infections (including encephalitis) or genital lesions (seen in adults). Diagnosis can be made clinically, or confirmed with DNA swabs or viral culture of vesicle fluid. Complications of herpes gingivostomatitis include herpetic whitlow, disseminated disease in immunosuppressed individuals, and herpes meningitis or encephalitis, although the latter is not preceded by known herpes infection in 80% of cases.
The mainstay of therapy is providing adequate analgesia and to ensure oral rehydration. Oral aciclovir may reduce the length and severity of symptoms when started early in the disease and should be considered, especially in severe cases. Topical aciclovir is ineffective.
Herpangina is an acute febrile illness usually affecting children in which there are ulcerated or vesicular lesions only over the posterior oropharynx; it is caused by enterovirus.
You are working in an ED which is in an area affected by severe floods. A 32-year-old man who has been helping his neighbours clear debris from flood-affected properties presents unwell with fever, rash, aching joints and lethargy.
Which ONE of the following is LEAST likely to be the causative illness in this patient?
Answer: C:
Floods can potentially increase the transmission of:
1- waterborne diseases, including:
2- vector-borne diseases, including:
It is important to consider these in any patient presenting with symptoms consistent with infection who presents during or in the few months following floods.
Symptomatology may narrow the diagnosis. Vibrio cholera causes watery diarrhoea and is spread by contamination of drinking water. Melioidosis due to the soil organism Burkholderia is seen typically in northern tropical Australia; it may present in a variety of ways including skin lesions (abscesses caused by infection of non-intact skin), pneumonia, splenic and liver abscesses. Mosquitoes transmitting dengue are predominantly seen in northern Australia. Ross River fever and Barmah Forest virus are transmitted by mosquitoes found throughout Australia; the typical presentation of illness is fever with arthralgia; there may also be a rash, deranged liver function tests (LFTs), and thrombocytopenia.
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