Children are begging by the roadside as they fight for survival putting them at risk of violence, according to aWorld Vision report (PDF).
Students are failing to attend class as they work on construction sites or walk with livestock to find pasture, the research shows.
"No-one to turn to"
Philippa Lei, Child Rights Manager at World Vision UK, said: “These children are facing appalling conditions.
"We’re doing all we can but the scale of this crisis means that many children – including those who are disabled or have lost their parents – simply have no-one to turn to.
"We are calling on the international community to urgently increase their help to target these children.
"Efforts must also be stepped up by the Government of Kenya to ensure families are able to access food even when schools are closed.”
Food and water
In Kenya, World Vision is delivering water and repairing water sources as well as supplying emergency food together with the World Food Programme to more than 300,000 people.
The charity is helping 485,000 people in Ethiopia, including giving emergency food to 61,000 internally displaced people and giving supplementary food to more than 25,000 people.
In Somalia (Puntland and Somaliland), World Vision is giving emergency food, water and running a food for work programme helping more than 45,000 people.
According to the UN, 385,000 children and 90,000 pregnant and breastfeeding women are affected by malnutrition in Kenya's north and north-eastern drought-affected districts.
This means one in five children are exposed to mortality due to malnutrition as well as preventable diseases such as malaria and stunted growth.
Across the region, some 11.5 million people are in desperate need of humanitarian assistance.
Read more from World Vision.