In the past three weeks, about 350 to 400 children in the Netherlands per 100,000 have been seen by family doctors for impetigo, a highly contagious skin infection. This is a jump from fewer than 300 per 100,000 in previous years. The current increase is both larger and earlier than the seasonal rise typically seen in summer, Nivel said. The Dutch National Institute for Public Health and the Environment (RIVM) also reported an increase earlier this month.

Impetigo is a highly contagious skin infection that mainly affects young children and usually appears around the nose and mouth. It causes red patches, bumps, and blisters filled with yellowish fluid. The blisters can burst, leaving areas covered with yellow-brown crusts that may itch or hurt.

The infection can spread when children scratch blisters and bacteria get onto their hands. The bacteria can then be transferred to other people through objects such as door handles.

RIVM recommends regularly washing hands with soap and water and avoiding scratching crusts. Impetigo can be treated with an antibiotic ointment. However, symptoms are often mild, and the infection usually clears up on its own, RIVM said. As a result, many people do not seek medical care, making it difficult to determine exactly how common the infection is.

Nivel said the recent peaks coincided with periods of unusually high temperatures measured by the Royal Netherlands Meteorological Institute, or KNMI. The institute has not investigated what caused the increase in cases.