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traction alopecia ( ta ) is a form of trauma - induced alopecia and results from continuous excessive pulling of hair shafts .
hairstyling is the most common cause of longstanding traction and usually results in alopecia of scalp margins .
when tension forces are not applied over the margin , for example , due to hair clips or wefts , an atypical pattern may result and the diagnosis can be challenging .
we present two cases of patchy ta due to video- electroencephalogram ( veeg ) test .
differential diagnosis with alopecia areata ( aa ) and trichotillomania ( ttm ) are discussed .
a 40-year - old epileptic woman complained of hair loss few days after a 12-day - long veeg test .
the patient presented several irregularly shaped alopecic patches [ figure 1a ] with black dots , yellow dots , and vellus hairs on dermoscopy [ figure 1b ] .
the clinical hypothesis of aa , ttm , or ta associated with telogen effluvium was made .
scalp biopsies showed increased telogen germinative units [ figure 1c ] and pigment casts [ figure 1d ] .
spontaneous complete regrowth was observed after 6 months of follow - up [ figure 1e and f ] .
case 1 ( a ) : clinical aspect ; ( b ) : dermoscopy - yellow dots , black dots , few vellus hairs ( videodermoscopy , 32 ) ; ( c ) : biopsy - no peribulbar infiltrate ( h and e , 40 ) ; ( d ) : vertical section - pigment cast ( h and e , 100 ) ; ( e ) : six - month follow - up - complete hair regrowth clinically and ( f ) : on dermoscopy a 44-year - old epileptic woman presented with hair loss few days after a 7-day - long veeg test .
scalp examination revealed several irregular alopecic patches associated with diffuse thinning over the crown [ figure 2a ] .
dermoscopy showed black dots , yellow dots , vellus hairs and increased shaft diameter variability on the patch border [ figure 2b ] .
female pattern hair loss ( fphl ) associated with patches of aa , ttm , or ta was considered as a clinical hypothesis .
after 6 months , full recovery of the alopecic patches was observed and topical minoxidil 5% was initiated for fphl diagnosis [ figure 2c and d ] . case 2 ( a ) : clinical aspect - patches of alopecia ( electrodes ref and f2 ) , diffuse hair thinning ; ( b ) : dermoscopy - black dots , yellow dots , vellus hairs .
notice hair variability ( videodermoscopy , 32 ) ; ( c ) : six - month follow - up - hair regrowth ; ( d ) : dermoscopy ; ( e ) : model - loosely braided hair , electrodes positions
a 40-year - old epileptic woman complained of hair loss few days after a 12-day - long veeg test .
the patient presented several irregularly shaped alopecic patches [ figure 1a ] with black dots , yellow dots , and vellus hairs on dermoscopy [ figure 1b ] .
the clinical hypothesis of aa , ttm , or ta associated with telogen effluvium was made .
scalp biopsies showed increased telogen germinative units [ figure 1c ] and pigment casts [ figure 1d ] .
spontaneous complete regrowth was observed after 6 months of follow - up [ figure 1e and f ] .
case 1 ( a ) : clinical aspect ; ( b ) : dermoscopy - yellow dots , black dots , few vellus hairs ( videodermoscopy , 32 ) ; ( c ) : biopsy - no peribulbar infiltrate ( h and e , 40 ) ; ( d ) : vertical section - pigment cast ( h and e , 100 ) ; ( e ) : six - month follow - up - complete hair regrowth clinically and ( f ) : on dermoscopy
a 44-year - old epileptic woman presented with hair loss few days after a 7-day - long veeg test .
scalp examination revealed several irregular alopecic patches associated with diffuse thinning over the crown [ figure 2a ] .
dermoscopy showed black dots , yellow dots , vellus hairs and increased shaft diameter variability on the patch border [ figure 2b ] .
female pattern hair loss ( fphl ) associated with patches of aa , ttm , or ta was considered as a clinical hypothesis .
after 6 months , full recovery of the alopecic patches was observed and topical minoxidil 5% was initiated for fphl diagnosis [ figure 2c and d ] . case 2 ( a ) : clinical aspect - patches of alopecia ( electrodes ref and f2 ) , diffuse hair thinning ; ( b ) : dermoscopy - black dots , yellow dots , vellus hairs .
notice hair variability ( videodermoscopy , 32 ) ; ( c ) : six - month follow - up - hair regrowth ; ( d ) : dermoscopy ; ( e ) : model - loosely braided hair , electrodes positions
ta is usually due to traumatic hair care practices and presents as bandlike hair loss of the frontal - temporal margin of the scalp , with the typical fringe sign .
patchy ta due to hair pins , clips or wefts is not marginal , and presents as localized areas of noncicatricial alopecia , mimicking aa or ttm .
dermoscopy of recent - onset ta differs from longstanding ta and shows mainly black dots and broken hairs .
vellus hairs and yellow dots might also be seen , but exclamation mark hairs are absent .
histology of recent - onset ta closely resembles ttm with increased catagen - telogen count and pigment casts within the hair canal .
the absence of peribulbar lymphocytic infiltrate or miniaturized hair follicles help differentiate from aa [ table 1 ] .
comparative findings between longstanging traction alopecia , recent - onset traction alopecia , acute patchy alopecia areata and trichotillomania veeg test is indicated in epileptic patients with infrequent convulsive episodes and includes the application of several electrodes to the scalp surface [ figure 2e ] . to our knowledge , these are the first reported cases of ta due to veeg electrodes .
we hypothesize associated hair cycle disorders , such as telogen effluvium and fphl , might have facilitated plucking in cases 1 and 2 , respectively .
the authors certify that they have obtained all appropriate patient consent forms . in the form the patient(s )
has / have given his / her / their consent for his / her / their images and other clinical information to be reported in the journal .
the patients understand that their names and initials will not be published and due efforts will be made to conceal their identity , but anonymity can not be guaranteed .
the authors certify that they have obtained all appropriate patient consent forms . in the form the patient(s )
has / have given his / her / their consent for his / her / their images and other clinical information to be reported in the journal .
the patients understand that their names and initials will not be published and due efforts will be made to conceal their identity , but anonymity can not be guaranteed .
acute traction alopecia is a diagnostic challenge when the external factor is not suspected or admitted . 
 we report two female patients with non - scarring patchy alopecia resulting from traction of video - electroencephalogram electrodes in which the clinical diagnosis of alopecia areata was suspected . 
 associated diffuse hair disorders might be implicated in these cases . 
 the correct diagnosis of traction alopecia is important in order to avoid unnecessary treatments .