Some diseases appear similar to urticaria and were therefore earlier classed together with it. Today we know that other disease mechanisms are behind them, and they are therefore no longer counted as urticaria. These diseases include, inter alia,

  • Urticaria pigmentosa (cutaneous mastocytosis)
  • Urticarial vasculitis
  • Hereditary angioedema

Urticaria pigmentosa (cutaneous mastocytosis)

This rare disease is an excessive accumulation of mast cells behind the—often brown or brownish—stains and small papules of the skin which can form wheals when they are subjected to friction. This disease usually makes its first appearance in the first few years of life, and often manifests a changing course after a few years. The exclusion of a so-called systemic form is recommended. Treatment of the symptoms is similar to that used in connection with urticaria.

Urticarial vasculitis

This is a vessel inflammation which creates hives and angioedema. This disease basically has little to do with urticaria and is treated differently.

Hereditary angioedema

Due to a genetic disorder in an enzyme (congenital, familial), angioedema may also occur. Antihistamines or corticosteroids do not help here, because histamine is not involved in the development of edemas, and an accurate diagnosis and therapeutic care is usually possible only in specialized centers or by physicians who are familiar with the disease.