Mice with the same allergy show different itching

On July 1, 2026, scientists in Japan announced a new finding about allergies^*1. They found that mice with the same allergy can have different symptoms. The reason was one small part of the cells that fight sickness. The scientists work at Hiroshima University, a university in Japan, and at RIKEN, a large research organization in Japan.

The study looked at dust mites^*2. Many people are allergic to them. A dust mite allergy can cause atopic dermatitis^*3, a skin disease that is often very itchy. Inside the body, T cells^*4 react to material from the dust mites. Each T cell has a receptor^*5 on its surface. The receptor is the part that recognizes the mite material.

The scientists made two kinds of cloned mice^*6 from T cells. No one had done this before. Both kinds of mice had T cells that reacted to dust mites. But the receptors on those T cells were different. Everything else in the genes^*7 of the two kinds of mice was exactly the same.

The scientists put mite material on the skin of the mice many times. Both kinds of mice got a skin disease like atopic dermatitis. Both made IgE antibodies^*8, and cells that cause inflammation^*9 moved into their skin. However, only one kind of mouse clearly scratched itself as the disease grew. The other kind did not. The skin of the two kinds of mice also had different amounts of a substance called IL-22^*10. This substance is linked to itching.

The genes of the two kinds of mice were the same, and only the receptor was different. So the scientists think the receptor may be one reason why allergies look different from person to person.

The paper was published on June 24, 2026, in the journal^*11 Allergology International.

1. *1 allergies: when the body reacts badly to something that is usually harmless, like dust or some foods
2. *2 dust mites: very small animals that live in house dust and beds; you cannot see them
3. *3 atopic dermatitis: a skin sickness that makes the skin red, dry and itchy
4. *4 T cells: a kind of cell in the blood that helps the body fight sickness
5. *5 receptor: a part on the outside of a cell that finds and holds one special thing
6. *6 cloned mice: mice that were made in a laboratory to have exactly the same genes as one cell
7. *7 genes: the instructions inside every cell that decide how a living thing grows and looks
8. *8 IgE antibodies: things the body makes in the blood when it has an allergy
9. *9 inflammation: when a part of the body becomes red, hot and swollen
10. *10 IL-22: the name of a substance that cells make to send messages to other cells
11. *11 journal: a magazine where scientists print their studies