A rare hereditary immune deficiency with skin involvement characterised by early-onset cold urticaria after generalised exposure to cold air or evaporative cooling and not after contact with cold objects. Additional immunologic abnormalities are often present - antibody deficiency, recurrent infections, autoimmune disease and symptomatic allergic disease. Caused by heterozygous deletion within the PLCG2 gene on chromosome 16q23. [from
SNOMEDCT_US]