A 5 yr old male child has multiple hyperpigmented macules over the trunk. On rubbing the lesion with the rounded end of a pen, he developed uicarial wheal confined to the border of the lesion. Most likely diagnosis:
FDE
LP
Uicaria pigmentosa
Uicarial vsaculitis
Gentle rubbing of a lesion causes local itching, erythema, and wheal formation after 2-5 minutes which may be present for 30 min or few hrs. This is the Darier's sign and is seen in uicaria pigmentosa.
Naevi and vessel related disorders