Skin-nontumor / Clinical dermatology
Other dermatoses
Urticaria (hives)

Author: Mowafak Hamodat, M.D., MB.CH.B, MSc., FRCPC (see Authors page)

Revised: 21 July 2016, last major update August 2011

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: Urticaria [title] skin

Cite this page: Urticaria (hives). PathologyOutlines.com website. http://pathologyoutlines.com/topic/skinnontumorurticaria.html. Accessed December 7th, 2016.
Definition / General
  • Pruritic, edematous plaques (wheals) due to localized mast cell degranulation and dermal microvascular hyperpermeability
  • Individual lesions fade within 24 hours, although episodes may last days to months
  • Commonly at pressure points
  • Causes: collagen vascular disorders, Hodgkin lymphoma, allergies (mediated by IgE, bridging by multivalent ligand), IgE independent allergies (contrast dye, opiates, aspirin [suppresses prostaglandins]), hereditary angioedema (deficiency of C1 esterase inhibitor causes uncontrolled complement component activation), infections, heat, cold, pressure, vibration
  • Angioedema: like urticaria, but in deep dermis / subcutaneous fat
Epidemiology
  • Ages 20 - 40 years are most common
Clinical Images

Images hosted on PathOut servers:

Breast skin, courtesy of Mark R. Wick, M.D.

Micro Description
  • Age of the lesion biopsied and nature of evoking stimulus may influence type and intensity of inflammatory response
  • Subtle edema (widely spaced collagen bundles), mild eosinophilic infiltrate and dilated lymphatics
  • Also dilatation of small blood vessels and lymphatics, often endothelial swelling
  • Cellular infiltrate is usually mild, perivascular, lymphocytes and a few eosinophils, occasional interstitial eosinophils
  • No vasculitis
  • Neutrophils often noted in early lesions, but relatively sparse; may be more prominent in physical urticarias
  • Transmigration of neutrophils through vessel walls may resemble vasculitis, but no fibrinoid change, hemorrhage or leukocytoclasis
  • In papular urticaria, inflammation is heavier than in other chronic urticarias, consists of superficial and deep perivascular lymphocytes and eosinophils
Micro Images

Images hosted on PathOut servers:

Breast skin, courtesy of Mark R. Wick, M.D.

Electron Microscopy Description
  • Platelets and other cells in lumen of mildly dilated vessels in upper dermis
  • Lymphocytes and dendritic cells are close to the vessels
  • Mast cells may be normal or degranulated
Additional References