black hair growth in a six year old

Hi
my six year old son is growing black hair on his forearms(upper). It has only occurred in the last few day with the left arm having an area the size of a chicken egg and the right arm having a much smaller patch. The hair is not thick and the skin is not discolored. I have inspected the rest of his body and have found no further hair growth particularly in the groin or underarms. Otherwise he is a normal developing boy doing very well at school.
Thank you
Sandy

[jagesh50]

Localised aquired hypertrichosis, as this is called generally occurs after trauma or injury.Cortisone application also can trigger such growth.Otherwise nothing more of worry,however do show to your doc.

[ponny]

Thankyou for the response. I'm a little embarrassed as I realised in the dead of the night that he had  henna tatoos on both forearms on our Bali holiday 3 weeks ago. The ink had worn off his skin  but dyed the hairs. Obviously I already need another holiday and it has at least given my friends a a good laugh
thanks again
Sandy

[jagesh50]

Relieved me too. ha ha