BOF: 50
A 26-year-old male presents complaining of a rash over his
upper trunk and arms. He is an Asian who has recently arrived in the UK.
On examination there are sharply demarcated depigmented
macules over the upper trunk and arms with fine scaling. There is no loss of
sensation over the macules, no loss of sweating, no lymphadenopathy, no
thickened nerves are palpable and the patient is afebrile.
Your next line of action in dealing with this patient would
be to:
a)
Take skin scrapings and examine them for fungi
b)
Do a TPHA test
c)
Take a skin biopsy
d)
Examine a slit skin smear for acid fast bacilli
e)
Give local treatment with topical imidazole
Answer:
a)
In a young otherwise well individual presenting with
depigmented macules with fine scaling, the most likely diagnosis is pityriasis
versicolor. This is caused by the yeast Pityriasis orbiculare (also known
as Malssezia furfur). It is more common in the tropics and subtropics and
commonly affects young adults.
The diagnosis is made on skin scrapings, which would show
spherical yeasts and short mycelia.
Treatment is with local applications of selenium sulphide,
local imidazoles or topical imidazoles.
Leprosy presents with hairless, hypopigmented, anaesthetic
lesions and they show absence of sweating, nerves may be thickened. This is an
unlikely diagnosis in this case and hence biopsy and slit skin smear are not
required.
In secondary syphilis the patient is bacteraemic and hence
systemically unwell with low-grade fever, malaise, headache, lymphadenopathy.
The rash consists of papules or plaques with scaling. The palms, soles and face
are commonly involved. This is unlikely in this case and hence a TPHA test is
not required.
Last Updated: 1/05/06
