ANGIOEDEMA,DR.D.K.JHA,M.D
Wednesday, August 15th, 2018Angioedema is characterised by sudden onset of swelling of eyelids,lips,tounge,genitals,dorsum of the hands and feet,which are visible on clinical examination and not clinically visible swelling of the gastrointestinal tract
Swelling of gastrointestinal tract present as pain abdomen of varying severity .Sometimes, acute severe pain like acute abdomen leading to unnecessary surgery.
Swelling involves the deeper subcutaneous layers.
There may be pain and itching but occasionally only pain is there.
It may take upto 72 hours for the resolution of sewlling.
It may be histamine related or non histamine related.
In histamine related angioedema,urticaria (wheals) will be present along with swelling
There may be a prodrome in the form of tightness or tingling of the area before swelling.
The most serious complication of angioedema is involvement of larynx in the form of laryngeal edema.
When the swelling involves the throat and uvula,it can readily be seen on clinical examination
It may cause complete obstruction of airway needing intubation and sometimes tracheostomy to save the life.
Fortunately,life threatening episodes are rare.
Dental procedures,with injection of procaine into gum is a common precipitant but laryngeal edema may be spontaneous.
There is no response to epinephrine,antihistamine and corticosteroids on the swelling.
If there is only swelling without urticaria,it is not associated with histamine and it may of two types-HEREDITARY AND ACQUIRED ANGIOEDEMA.
HEREDITARY ANGIOEDEMA can be of three types;Type 1-reduced production of C1 inhibitor
Type 2-sufficient production but decreased function of C 1 inhibitor
Type 3-Estrogen dependent,due to mutation in factor xii seen mostly in women
ACQUIRED ANGIOEDEMA can also be of three types;Type 1-associated with reduced C 1esterase inhibitor
Type 2-Drug induced,most common offending drug is ACE inhibitor
Type 3-Histamine dependent regarded as urticaria without wheals
HEREDITARY ANGIOEDEMA is an autosomal dominant disease.
ACQUIRED ANGIOEDEMA may be seen in association with neoplasia,lymphoproliferative disorders and rarely infections.
In case of suspicion of hereditary angioedema type 1 and type 2, decreased levels of serum C 4,C 1inhibitor and decreased function of C 1 inhibitor should be assessed.
TREATMENT
Acute therapy is required during life threatening episodes,which is fortunately rare.
Specific treatment is concentrate of human C1 inhibitor ,the availability of which is limited
The approved drug is BERINERT,used as an intravenous formulation in the dose of 20 unit/kg
In case of non availability of this specific reatment,FFP(fresh frozen plasma) may be used which is least specific but widely available.
Bradykinin type 2 receptor antagonist ICATIBANT is approved for the age of 18 years and older
All treatmens are most effective when they are given early after onset of signs and symptoms
It may take 1-4 hours for the start of action after giving the drug.
Icatibant can be given in ACE inhibitor induced angioedema
Icatibant can be stored on room temperatue and can be given subcutaneously
Icatibant is licensed for home treatment in Europe.
CINRYZE-Purified C1-INH is approved for prophylaxix after acute attack in adolescents and older children
It is given in the dose of 1000 units intravenously twice a week
Danazol is another drug being used as short term prophylaxix ,but it is not given in children,
due to the side effects of premature closure of epiphysis
Danozol increases the production of C1 inhibitor in liver,
For histamine related angioedema, non sedating antihistamine is the drug of choice
In case of no response to usual dose of nonsedating antihistamine ,the dose may be increased to 4 times
REFERENCES:
- Borzova E and Gratton C ,Angioedema.In Zuberbier Tet al.Urticaria and AngioedemaBerlin:Springer Verlag 2010.122.
- Bindslev-JensenC,CanonicaGV,Church mk,GimenzArnou AM et al. eaaci/ga2lan/edf/wao Guideline .Treatment of Urticaria .Allergy2010;64:1417-1426
- Nelson Textbook of Pediatrics 20 e