Mohamed, 11, first saw the unsightly welts caused by the disease appear on his face three months ago, and they keep growing.
"It's a fly that comes from pomegranates, it bites you and you catch the Aleppo button," he says.
The welts cover his nose and have cropped up around his mouth. While painless, they could leave scars that last for life. His mother, sister and cousins have also contracted the same infection.
The disease, which is not fatal but weakens the immune system, was largely confined to the countryside of Aleppo province until the civil war.
But as the conflict forces people from their homes and into the city, once Syria's economic hub, the disease has taken hold in Aleppo like never before.
"Between 200 and 250 people with leishmaniasis come for treatment" each day, according to 23-year-old Ali, a medical volunteer at a makeshift clinic in the city.
In the hallway where he receives the latest patients, a dozen men, women and children offer up their faces and arms, covered with the welts.
In the neighbouring room, under a sheet, a man pours the antiseptic Betadine over his leg. The disease has devoured all the skin on his calf.
But most of those affected are children, with Ali saying they represent around 50 percent of those with leishmaniasis in Aleppo.
"The children spend most of the time outside of the house and they play in the street, among the rubbish," says Aisha, a 16-year-old student who has worked as a nurse since the revolution began.
To be protected from the disease, people should at the very least be sleeping under mosquito nets, Ali says.
"But at 1,000 Syrian pounds ($10), how can a family with several children buy one for each of them?"
With summer approaching and the number of flies expected to multiply, one former physics student has decided to take matters into his own hands.
Rabie, 30, working with his cousin and a friend, tours the Tariq al-Bab neighbourhood armed with a strange machine that spits out white smoke.
"It's petrol mixed with insecticide," he said, a thin surgical mask on his face.
"We decided to organise ourselves now that summer is coming, to kill the flies responsible for the transmission of the disease to humans before they begin biting people," he said.
Before fighting began in Aleppo nine months ago, local authorities carried out an insect eradication campaign each year.
But this year, in areas of the city held by rebels, Rabie and his friends are carrying out their work from a small pick-up truck, with funds collected from rebel brigades and opposition groups.
The machine was purchased in neighbouring Turkey for $1,500 and is able to cover the dozen or so streets of each district in around an hour.
Faced with the mountains of rubbish that cover every corner of this former economic powerhouse, he knows his efforts are unlikely to make serious inroads.
But he persists nonetheless, because at the clinic, they have already opened the last box of Glucantime, a French drug used for treating leishmaniasis that is virtually impossible to come by in Syria.