A patient had seven irregular hyperpigmented macules on the trunk and multiple small hyperpigmented macules in the axillae and groins since early childhood. There were no other skin lesions. Which is the most likely investigation to support the diagnosis?
A. Slit lamp examination of eye
B. Measurement of intraocular tension
C. Examination of fundus
D. Retinal artery angiography
Correct answer : A. Slit lamp examination of eye
The irregular hyperpigmented macules since early childhood are probably cafe au lait macules. Presence of 6 or more cafe au lait macules is diagnostic of neurofibromatosis type I even when cutaneous neurofibromas are absent. Lisch nodules on the iris can be demonstrated by slit lamp examination and it helps support the diagnosis.