Because of climate change, heat waves, storms, heavy rainfalls, and floods are now occurring in areas that seldom experienced these phenomena before. “Extreme weather events are rare, but in terms of their extent, duration, and scale, they are unusual. And they are increasing due to climate change,” said Andrea Elmer, MD, an internal medicine and pulmonology specialist at the DKD Helios Clinic in Wiesbaden, Germany. She spoke at the Congress of the German Society for Pneumology and Respiratory Medicine.
Dr. Elmer referred to the 2023 status report by the Robert Koch Institute and the 2023 Synthesis Report by the Intergovernmental Panel on Climate Change, in which the likelihood of extreme weather events was acknowledged to be significantly higher than previously recognized. “Knowing about such extreme weather events is important to assess the consequences for our patients and to identify possible medical care needs,” said Dr. Elmer. She focused on the effects of platanus (plane tree) cough and thunderstorm asthma.
Platanus Cough
The symptoms worsened when the children left the building and waited in the schoolyard. Initially, a chemical attack with irritant gas was suspected because the school is located near an industrial area. There were no indications of a pollen cloud.
Eventually, doctors and firefighters found that the symptoms were caused by platanus cough, which is induced by the fine star-shaped hair found on young platanus leaves, bark, young branches, and buds. If strong winds move the leaves after prolonged dryness, these trichomes can break off when touched, creating platanus dust.
At that time, there were unusual climatic conditions. The temperature was 29 °C, it was dry, and wind gusts reached 50 km/h. The schoolyard was enclosed and densely planted with tall, old plane trees. Initial symptoms occurred in classrooms with open windows.
Twenty-five children had to be admitted to the hospital. Treatment included lorazepam and salbutamol. All students had normal oxygen levels, and the symptoms were reversed.
Cough or Allergy?
The clinical differential diagnosis for an allergy is quite simple, said Dr. Elmer. Platanus cough mainly shows symptoms of irritation, a feeling of a foreign body, and scratching in the eyes, throat, and nose. Coughing can also occur. In an allergy, there is often a runny nose and itching in the eyes and nose. Such allergic symptoms do not occur with platanus cough.
It should also be noted that the sensitization rates for a platanus allergy in Germany range between 5% and 11%. “Having so many platanus allergy sufferers in one place was relatively unlikely,” said Dr. Elmer.
She expects an increase in cases of platanus cough, especially in cities with dense construction, such as in narrow schoolyards. High concentrations of platanus dust can occur, especially when it is warm, dry, and windy. “Platanus cough does not occur every time we walk under plane trees. It strongly depends on warmth, dryness, and wind,” said Dr. Elmer.
Patients can protect themselves by avoiding skin and mucous membrane contact under appropriate climatic conditions and by wearing protective glasses and masks. Leaves and branches should not be swept but vacuumed. “Under no circumstances should plane trees be cut down. We need trees, especially in cities,” said Dr. Elmer. Moreover, the trichomes act as biofilters for air pollutants. In critical environments such as schoolyards, seasonal spraying of plane trees with a mixture of apple pectin and water can prevent the star hair from breaking off.