urticaria represents a transient edema within the dermis ; the individual urticarial lesions characteristically clear within hours .
it is a vascular reaction of the skin , triggered by many known as well as unknown factors that result in liberation of vasoactive substances such as histamine , prostaglandins , and kinins .
most lesions of urticaria are small , less than 10 mm , but individual large lesions of 610 cm may occur  the so - called giant urticaria .
clinically , urticaria is classified into the acute ( duration < six weeks ) and chronic ( duration > six weeks ) types .
 episodic urticaria , which occurs intermittently but recurrently over months or years , is also recognized .
acute urticaria in children can be treated symptomatically needing no further investigations , while chronic urticaria requires a detailed search for trigger factors .
chronic urticaria is relatively less frequent in children compared to adults , with only occasional documentation of autoimmune urticaria .
the etiology of chronic urticaria ( cu ) in childhood remains incompletely understood because of limited data available on children .
the objective of this retrospective study is to examine some of the possible etiology of urticaria and its response to specific treatment in children , after evaluation of available data .
a retrospective hospital data - based study study was conducted in children who had attended the out - patient departments of dermatology and pediatrics from june 2005 to may 2010 .
80 patients suffering from urticaria ( excluding physical urticaria ) between the ages of 1 and 14 years were examined .
detailed history of these children included food allergies , drug intake , personal and family history of atopy , insect bites , infections , and infestations .
the initial evaluation consisted of a thorough history , detailed physical examination , and basic laboratory tests such as complete blood count , stool microscopy , and urine examination , to rule out a focus of infection .
specific tests including thyroid function tests , thyroid anti peroxidase antibodies , serum ige levels , asst , x - ray of paranasal sinuses , and investigations for hepatitis a virus were done after baseline investigations .
80 children , comprised 49 males and 31 females with majority ( 44 , 55% ) of children under the age group of eight and eleven years [ table 1 ] .
chronic urticaria was observed in 56.25% of these children and the remaining had acute urticaria .
a majority of parents gave a preceding history of infections and the second most common observation of parents was aggravation of urticaria after food [ table 2 ] . during detailed history taking , the various food materials found to be aggravating the urticaria were peanuts , eggs , cheese , and chinese food in that order .
drugs aggravating urticaria were mefanamic acid , ibuprofen , nimesulide , ofloxacin , ampicillin , and cotrimoxazole .
a complete blood count showed the hemoglobin to be less than 10 gm% in eight children .
demographic features of patients detailed histories obtained microscopic examination of the urine showed pus cells in 16 and ova / cysts were documented in the stool examination of 10 children .
the autologous serum skin test was positive in 17 and thyroid dysfunction was documented in 12 patients .
out of the 12 patients four had hyperthyroidism and the remaining eight had hypothyroidism , two among the eight were positive for thyroid antiperoxidase antibodies . raised serum ige levels were present in 15 .
a majority of the children were treated with antihistamines ; a definite association of suspected underlying cause with specific treatment was found in 16 ( 20% ) .
out of 16 , five were treated for worms ( albendazole ) , three received treatment for upper respiratory tract infection ( two were given amoxicillin and clavulinic acid , one was given azithromycin ) , two each had received specific treatment for urinary tract infection ( nitrofurantoin ) , hypothyroidism ( thyroxine ) , and removal of an offending drug , and one each was treated for hepatitis a virus and dental caries .
the episode is short - lived and simply a nuisance , but for a few it may be a sign of a serious disorder .
in contrast to the ease of its diagnosis , the etiological factors are often difficult to determine . the natural history of urticaria in children is distinct from that in adults .
urticaria is a common disease that can persist or recur over long periods of time , spanning years , causing distress , and at times can be life - threatening . as a cause
is often not found , it presents the physicians with a diagnostic and therapeutic challenge . due to the scarcity of data regarding the etiological factors of urticaria in children ,
this retrospective data - based study was undertaken in an effort to determine various etiological factors of childhood urticaria .
urticaria in childhood is common ; according to different studies , 15  20% of children suffer from at least one episode of urticaria by adolescence.[47 ] in our study 56.25% had chronic urticaria ; another study from a tertiary referral center from india reported that 80% children had cu out of 44 children . in this study ,
a definite association to an underlying cause was present in 37.5% of the patients , although suspicion was entertained in 66.25% of the patients , in the remaining there was no response seen on offering specific treatment .
a review of 94 children with cu revealed that 58% became symptom - free for six months or more , whereas the cause in this study was determined in only 16% . in another report of 226 children ( age : 1  14 years ) with cu , only 21% were determined to have a causal factor .
only a few studies have been conducted on the etiological factors of urticaria in children and few of these studies in children showed that in more than 70% of the cases , the exact cause could not be identified . in our study , asst was positive in 17 of the 80 ( 21.25% ) children ; another study of asst in children showed a positive reaction in 35.29% of the patients . in western literature ,
a positive asst was reported in 25  45% of adult patients with chronic idiopathic urticaria .
a positive test is suggestive , but not the diagnostic of an autoimmune basis for a patient 's urticaria .
confirmation is needed by in vitro testing of the patient 's serum for anti - fcr1 or anti - ige autoantibodies .
an autologous serum skin test is a fairly good baseline test for diagnosing suspected cases of autoimmune urticaria , particularly where a basophil histamine releasing test is not available .
it has good sensitivity and an even better specificity for detecting autoantibodies , even in children .
management of urticaria in children requires a detailed structured history , a complete review of systems , baseline investigations , and other specific in vivo and in vitro tests .
various studies suggest that in a majority of pediatric patients , the history of a preceding infection , particularly respiratory infection , is obtained.[571314 ] in our study also , a majority ( 20% out of 32.25% ) of the patients had infections as the underlying cause [ table 4 ] . details of patients showing response to specific treatment exhaustive
work up with extensive laboratory , technical diagnostics , challenge tests and skin prick testing should be reserved for individual cases following detailed history .
a well designed structured study is still in need to find the etiological factors of urticaria in children .
 background : urticaria is a common dermatological manifestation in adults with relatively infrequent occurrence of chronic urticaria ( cu ) in childhood . the etiology of urticaria in childhood remains incompletely understood because of limited data on children.objective:we carried out this retrospective data - based study to determine different etiological factors and response to treatment in pediatric patients presenting with urticaria.materials and methods : eighty children ( m : f 49 : 31 ) between the ages of 1 and 14 years , who presented with urticaria excluding patients of physical urticaria attending the outpatient department of pediatrics and dermatology were included in the study . 
 patients were evaluated after taking a detailed history , doing a thorough physical examination , and basic laboratory investigations . 
 specific in vivo and in vitro tests were performed after the initial evaluation and consent of patients.results:out of eighty patients , 35 ( 43.75% ) presented with acute urticaria and 45 ( 56.25% ) gave a history of chronic urticaria.cu . 
 an underlying cause was suspected in 53 cases ( 66.25% ) , although a definite association with response to a specific treatment was correlated in 30 ( 37.5% ) . 
 infection was the most common underlying causative factor . 
 underlying thyroid dysfunction was observed in 12 patients , of whom two had thyroid anti peroxidase antibodies . 
 autologous serum skin test was positive in 17 patients.conclusions:in the present study infections were the most common etiological factor for urticaria in children . 
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION