In primary school, children teased him with names like "vampire" and "botak".
Raffles Institution (RI) graduate Loh Yih Hang, 18, has no sweat glands and minimal salivary glands.
He looks older than he is, with no hair and teeth missing.
"Back then, I was a bit uncomfortable with it and I didn't really know how to deal with it... but my parents told me not to care about what other people say about me."
Yesterday, he collected his A-level results from the school where he was a student for six years. He scored straight As for all his subjects - H2 physics, chemistry, mathematics and geography, as well as H1 General Paper and project work. Mr Loh hopes to pursue computer science in a local or overseas university.
Diagnosed at birth with hypohidrotic ectodermal dysplasia, he is also susceptible to heat stroke as the condition makes him unable to sweat and expel heat.
But he also developed a "thick skin" to block the nasty comments.
"I also made friends who were accepting of my condition, all the way from primary school to now."
Today, he is unfazed by the looks he gets, and has come to accept that his medical condition is part of who he is. He even jokes about it.
"Sometimes my friends talk about wanting to change their hair colour, and I'd say I wish I could dye my hair too," he said. "I'm actually quite happy when people ask me about my medical condition, rather than just stare."
He has learnt to manage it over the years, by staying in the shade and keeping a water bottle by his side, in case he needs to drink more.
"If I get very hot, I would pour some water over my head to cool down," he said. "I will always have this medical condition, it's not something that can be cured. I have become more confident in sharing my life story."
In school, he joined physical education lessons as often as he could, and swam every week to keep fit.
He was part of RI's prefectorial board in his first four years, and joined the student council in his junior college years.
He also volunteered weekly at Meet-the-People Sessions in the Toa Payoh-Novena area.
"I try to do everything to the best of my abilities, and participate as much as I can," said the oldest of three boys, whose parents are business owners. "Anyone who has a medical condition has his own set of challenges, which no one will be able to fully understand," he said, adding that this condition has helped him learn to take problems in his stride.
"If we see all these challenges as ways to make life more interesting, it will be easier to overcome them."