If the patients complaints are for less than 6 weeks the condition is acute and Ig E involvement is expected. Complaint for more than 6 weeks is chronic and Ig G is involved.
There are several causative factors of the disease (10 I's and 3 P's!):
- Iatrogenic- Tetracyclines, Ace-inhibitors, Sulfa group drugs, NSAID's and Penicillins.
- Ingestion: beef, fish, chicken, wheat, eggs, foods containing colored dyes,sea-food.
- Injection: anti-diptheria serum, anti-tetanus serum, anti-snake serum.
- Inhalation: pollen grains, smoke, dust.
- Infections: Hepatitis B/C, H Pylori.
- Infestaion: hook work, round worm.
- Immune Disorders: SLE, rheumatoid arthiritis, chaugat's disease.
- Irridation: x-rays, radiotherapy.
- Internal malignancy: leukemia, lymphoma, sarcoma, carcinoma.
- Psycogenic: stress
- Physical: exposure to sea water, extreme weather conditions.
- Physiological: pregnancy.
Antibodies(IgE) are produced against the causative antigen. These antibodies recruit mast cells, basophils and eosinophils which consequently release mediators - histamine, serotonin, bradykinin, prostaglandins, leukotriens, kimases and tryptases. These mediators bind their respective mediators and causing the clinical manifestations of the disease.
This disease can manifest in four ways according to severity:
1) it is limited to the skin and the typical lesions are seen on examination.
2) Angioedema: most commonly associated with deficiency of C1 esterase inhibitor(controls clotting mechanism- factor 12). It appears as swelling mostly around the mouth/throat/tongue (muco-cutaneous junction) and may be itchy. Sensations are decreased as nerves may be compressed).
3) Anaphylaxis: skin, muco-cutaneous junction and systemic involvement. Causes respiratory distress and colicky abdominal pain. This stage is further divided into:
- immediate: symptoms occuring within 2 hours of exposure and involving Ig E
- delayed: symptoms occuring within hours and involving Ig G.
Dermograph- when the insulting agent is stroked in a linear fashion along the skin, the rash appears along the same region os contact.
Oral steroids- acute: short courses of high doses.
chronic: long courses of low doses.
Mast cell stabalizers