Urticaria (Hives)

 

Epidemiology:

    • 20-40y

 

Common sites:

    • trunk
    • distal extremities
    • ears

 

Gross features:

    • pruritic edematous papules and plaques (wheals)
    • lesions develop and fade within hours

 

Histologic features:

    • subtle
    • sparse superficial perivenular infiltrate
      • mononuclear
      • rare neutrophils
      • eosinophils maybe
    • collagen bundles more widely spaced
    • dilated superficial lymphatic channels

 

Immunophenotype:

Marker:

Sensitivity:

Specificity:

 

 

 

 

Molecular features:

    •  

 

Other features:

    • localized mast cell degranulation
    • angioedema is similar but involves subcutaneous fat
    • persistent episodes may herald underlying disease (minority of cases):
      • collagen vascular disorders
      • Hodgkin disease
    • Most are IgE dependent
    • Some are IgE independent:
      • Opiates
      • Antibiotics
      • Curare
      • Contrast media
      • Aspirin
      • Hereditary angioneurotic edema (complement-mediated urticaria)

 

References:

    •