Indusium: the case made by an insect larva: a membranous layer of the embryo of Locustidae below the serosa. Explanation of Terms Used in Entomology John. B. Smith. serosa: the outer membrane that envelops the forming embryo, the amnion and the remainder of the egg. Explanation of Terms Used in Entomology John.
In essence, your body forms an allergic reaction to stress. Unfortunately, stress can not be eliminated with histamine, so instead, the histamine just causes hives to appear on your face, neck, chest and other parts of your body.
Chest/Abdomen/Back. Common causes of itching of the skin on the main part of the body may include contact dermatitis, atopic dermatitis, scabies infection, psoriasis, and folliculitis. Arms. Itching of the arms, especially the area at the bend of the elbow, can be due to atopic dermatitis.