Chronic urticaria and dental infection

Chronic spontaneous urticaria: An etiopathogenic study

Importance:

Exact etiopathogenesis of chronic spontaneous urticaria (CSU) remains elusive. Infections, pseudoallergens, autoimmunity, and contact sensitization are various postulated factors. Few studies are available measuring cytokine levels in CSU.

Objectives:

The aim was to study various etiological factors of CSU and levels of IL-6 and IFN-ϒ in cases and controls, and correlation between various etiologies with the levels of the abovementioned interleukins in the cases.

Design:

Case-control study performed over 2 years with no follow-up of the participants.

Setting:

It was a referral-center-based study.

Participants:

Sixty patients of CSU and equal age and sex-matched healthy controls were recruited on the basis of convenience sampling.

Exposures:

Biochemical and hematological investigations with hepatitis serology, thyroid function tests, anti-thyroid antibodies, and levels IL-6 and IFN-ϒ were performed in all cases and controls. All cases were subjected to ASST. Cases with all above negative tests were patch-tested with Indian standard series. Urticaria activity score (UAS7) was calculated for all the cases and repeated in patients with positive etiological factor after 3 weeks (improvement after allergen or drug avoidance, treatment of infection).

Outcomes:

To study the various etiological factors (food, infection, autoimmunity, autoreactivity, and contact sensitization) and the levels of IL-6 and IFN- γ in patients of chronic spontaneous urticaria.

Results:

Etiology was ascertained in 75% of patients (autoimmunity: 50%, contact sensitization: 21.67%, food and drug allergy: 1.67% each). Mean values of the interleukins and anti-thyroid antibodies were significantly higher in cases versus controls. Levels of IFN-ϒ were significantly elevated in patients with higher UAS7 scores.

Conclusion:

Antithyroid antibodies, ASST, and patch testing are important tools and should be considered in patients of CSU after a thorough history and history-based workup. Elevated levels of IL-6 and IFN- ϒ in cases suggest that both Th1 and Th2 type of immune responses are implicated in pathogenesis of CSU.

Urticaria and infections

Urticaria is a group of diseases that share a distinct skin reaction pattern. Triggering of urticaria by infections has been discussed for many years but the exact role and pathogenesis of mast cell activation by infectious processes is unclear. In spontaneous acute urticaria there is no doubt for a causal relationship to infections and all chronic urticaria must have started as acute. Whereas in physical or distinct urticaria subtypes the evidence for infections is sparse, remission of annoying spontaneous chronic urticaria has been reported after successful treatment of persistent infections. Current summarizing available studies that evaluated the course of the chronic urticaria after proven Helicobacter eradication demonstrate a statistically significant benefit compared to untreated patients or Helicobacter-negative controls without urticaria (p < 0.001). Since infections can be easily treated some diagnostic procedures should be included in the routine work-up, especially the search for Helicobacter pylori. This review will update the reader regarding the role of infections in different urticaria subtypes.

Management and diagnostic guidelines for urticaria and angio-oedema

These guidelines for management of urticaria and angio-oedema have been prepared for dermatologists on behalf of the British Association of Dermatologists. They present evidence-based guidance for treatment, with identification of the strength of evidence available at the time of preparation of the guidelines, and a brief overview of aetiology, diagnosis and investigation.

Mechanisms underlying urticaria

Urticaria, a clinically distressing disorder, is dermal oedema resulting from vascular dilatation and leakage of fluid into surrounding tissue, often in response to histamine (and other mediators) released from mast cells. A clear history of events surrounding the onset, together with laboratory investigations, in some cases allows us to find a cause and eliminate it.