Neck itching can be caused by insect bites, allergic reactions to perfumes or other chemicals, exposure to poison ivy, eczema, chickenpox, scabies, pinworm, psoriasis and stress, according to HealthGrades. Additional causes of neck itching include exposure to extreme temperatures, head lice, atopy, some metals used in jewelry and laundry detergents.
Itching caused by allergies can manifest suddenly and may precede anaphylactic shock, explains HealthGrades. Many forms of neck itching are easily treated at home or under the supervision of a doctor. If neck itching is accompanied by difficulty breathing, a visible rash, alterations of consciousness, tightening of the throat or facial swelling, seek emergency medical assistance immediately.