Theme: Infectious diseases
A. Human Immunodeficiency Virus (HIV)
B. Human Coronavirus-NL63 (seasonal coronavirus)
C. Scarlet fever
D. Chickenpox
E. Hand, foot and mouth disease
F. Kawasaki Disease
G. Parvovirus B19 Infection
H. Genital herpes
I. Non-specific viral rash
J. Schistosomiasis
Please select answers to the questions from the list of infectious diseases presented.
- Which of the above is a notifiable disease?
Scarlet fever
Registered medical practitioners have a statutory duty to notify the local health protection team of suspected cases of certain infectious diseases. Scarlet fever is the only condition above on the list of notifiable diseases.
Human Coronavirus-NL63 is an example of a seasonal coronavirus which causes a generally mild and self-limiting respiratory tract infection and is not notifiable. COVID-19 (SARS-CoV-2) is a notifiable disease.
None of the other conditions listed are notifiable diseases in the UK.
- A 5-year-old child is bought to see you with a rash. His mother reports that he has had a sore throat and low-grade fever for a couple of days. Yesterday he developed a spotty rash on his face, particularly around his mouth, and she has now noticed this spread to his extremities, including his hands, feet and buttocks. He is up to date with immunisations and has had a chickenpox vaccine privately.
What is the most likely diagnosis?
Hand, foot and mouth disease
Hand, foot and mouth disease is the most likely diagnosis. It often presents with a prodrome of sore throat and fever, and then a rash develops initially on the mouth and lips, then spreads to the hands and feet. The rash may also affect the genitals and buttocks but rarely elsewhere in the body. It is most commonly caused by the Coxsackie A16 virus.
This child has been vaccinated against chickenpox. This is part of the childhood vaccination schedule in some countries and is available privately in the UK. The vaccine is over 90% effective so chickenpox is unlikely in this child. It presents with a very itchy vesicular rash primarily affecting the head, neck and trunk. It can also affect the limbs and mouth.
Parvovirus B19 infection is the causative agent of erythema infectiosum (fifth disease). It typically presents with a mild prodrome of headache, runny nose, sore throat and low-grade fever followed by a symptom-free period of 7-10 days, after which a classic ‘slapped cheek’ rash appears. A few days later an erythematous macular rash develops on the extremities, mainly on the extensor surfaces.
Many viruses can cause a rash, in addition to other symptoms such as fever and cough, which is not characteristic enough to identify the virus causing the rash. This can be described as a non-specific viral rash. However, this child’s presentation is typical of hand, foot and mouth disease.
- Which of the above conditions requires treatment with antibiotics?
Scarlet fever
Scarlet fever presents with a fever followed by a sandpaper rash 1-2 days later, typically on the neck, chest and scapular region. The trunk and legs are then affected later. Patients may have a sore throat, haemorrhagic spots on the palate, red exudative tonsils, cervical lymphadenopathy, headache, vomiting, abdominal pain, and myalgia. They may also get skin peeling and white tongue (desquamation). Scarlet fever is a bacterial infection caused by Group A beta-haemolytic streptococci. It is typically treated with 10 days of oral penicillin, or azithromycin if penicillin-allergic. It is a notifiable disease in the UK.
Kawasaki disease is an idiopathic systemic vasculitis mostly affecting children aged 6 months to 5 years. The mainstay of treatment is aspirin and intravenous immunoglobulin (IVIg).
Schistosomiasis is an infection caused by a parasitic worm and is treated with praziquantel.
The other conditions listed are viral infections and generally, antibiotics are not required unless there is a secondary bacterial infection.
