allergic reaction traffic sign on blue sky

allergic reaction traffic sign blue sky background allergy symptoms anaphylaxis hypersensitivity immunological response allergen exposure rhinitis skin rash sensitivity respiratory distress asthma immune system itching eczema conjunctivitis histamine release swelling hives dermatitis trigger source testing inflammation avoidance immunotherapy sensitization contact food airborne allergens reactions allergist consultation sensitivities management conditions cross-reactivity medication attack cascade dermatosis relief disorders identification