A 45-year-old man has developed an annular rash with a scaly edge on his thigh. The rash has been spreading. He has some general aches and pains.
What is the single most useful investigation?
A . ANA
B . Skin scrap for mycology
C . Skin swab for bacteria
D . Biopsy lesion
E . Lyme antibodies
Answer: E
Explanation:
Explanation Spreading annular rash suggests erythema migrans of lyme disease.