Quiz
Leg rashes and unwell – 10 cases

Each of these patients is unwell and presented with a rash on their legs.

For each of the ten cases, study the image(s) and then answer the questions. You can click on the image to view a larger version if required.

Each case should take approximately 2 minutes to complete. There is a list of suggested further reading material at the end of the quiz.

Case 3

A student returned from a gap adventure in Scandinavia and a few days later presented with a rash on her left thigh associated with malaise. She had been camping in a farmer's shed and had been told to watch out for tick bites, although she did not recall receiving one. The rash resolved during a two-week course of doxycycline 200mg daily.

What is the name of the skin condition?

Erythema chronicum migrans

What underlying systemic disease(s) or condition is it caused by?

Erythema migrans is due to Lyme borreliosis in more than 90% of cases.

Erythema migrans is an erythematous, expanding annular plaque with a bull's eye appearance, which typically appears a few days after an infected tick bite. Other symptoms may include fever, arthralgia, headache and myalgia. The diagnosis is made clinically as serology may take several weeks to obtain and is negative in 60%, as in this patient.

Lyme disease is due to spirochaetes, Borrelia burgdorferi, B. garinii and B. afzelii transmitted via Ixodes ticks. It is a multisystem infection and may result in disease of the eyes, heart, joints, nervous system and genitourinary system. Borrelia may also give rise to lymphocytoma cutis and acrodermatitis chronic atrophicans. All its manifestations are rarely seen in New Zealand, as endemic ticks do not carry the causative spirochaetes.

Mark question

Previous Question Next Question

Quiz Leg rashes and unwell – 10 cases

Case 3

Sign up to the newsletter

Quiz
Leg rashes and unwell – 10 cases