the frequency of umbilical cord blood transplantation ( cbt ) from unrelated donors has increased among adult patients who require allogeneic hematopoietic stem cell transplantation but have no suitable bone marrow or peripheral blood stem cell donors .
although very rare , there are reports of patients who have undergone cbt and subsequently developed cutaneous disseminated vzv infection .
there is a lack of detailed information on the clinical course and serological findings in such cases . here
, we report in detail the clinical course and serological findings of a case of vzv reinfection in an adult post cbt , which appeared clinically to be varicella and followed a severe and prolonged course .
a 50-year - old japanese man with a history of cbt for acute lymphoblastic leukemia in march 2009 developed remittent fever and fatigue on 25 august 2010 .
subsequently , he noticed an itchy skin eruption and visited our dermatology department on 1 september , 2010 .
physical examination revealed sparsely distributed vesicles , some with umbilication , and small erythematous erosions on the face , anterior chest , upper back , and upper extremities [ figure 1a , b ] .
histological analysis of a vesicle showed an intraepidermal blister containing degenerated balloon cells [ figure 1c , d ] . within a few days
, there was widespread eruption of vesicles and bullae over the body [ figure 1e , f ] and the fever became continuous .
clinical appearance of the skin lesions at day 3 : ( a ) erythematous erosion in the region of the left eyebrow and ( b ) an umbilicated vesicle .
histological findings in a vesicle on the right forearm : ( c ) acanthosis with intraepidermal blisters and a mild perivascular infiltration of lymphocytes in the upper dermis ( hematoxylin and eosin ; original magnification 40 ) and
( d ) an intraepidermal blister containing degenerated balloon cells ( hematoxylin and eosin ; original magnification 200 ) . clinical appearance of the skin lesion at day 10 : scattered vesicles and bulla , some of which became erosions on the chest , abdomen ( e ) , and back ( f ) he was admitted for intravenous acyclovir ( 10 mg / kg / day ) for 5 days , with a reduced dose as the patient had renal dysfunction of an unknown cause .
the skin lesions responded promptly to therapy : no new skin lesions developed and the bullous lesions began to scab , though some lesions remained active .
the patient was discharged after 5 days of intravenous acyclovir , with oral valacyclovir ( 20 mg / kg / day ) advised for a further 9 days . by september 21 ,
we measured the serum levels of anti - vzv igg and anti - vzv igm by enzyme - linked immunosorbent assay kits ( enzygnost anti - vzv / igg and enzygnost anti - vzv / igm , dade behring , deerfield , il , usa ) on days 3 and 33 after the appearance of the skin eruption . the values of anti - vzv igg were expressed in international units ( i.e. , miu / ml , with values < 57.0 miu / ml being considered negative ) ; the measurement of anti - vzv igm were expressed as a cut - off index ( i.e. , < 1.0 : negative , 1.02.0 : indeterminate , and > 2.0 : positive ) .
serum anti - vzv igg was negative on day 3 and 260 miu / ml on day 33 .
the former is considered to play a more important role in the host defense against vzv , since vzv is cell - associated during active infection .   as cord blood contains naive t - cells but no antigen - specific memory t - cells , primary vzv infections by exogenous vzv
are expected to occur frequently in cbt recipients .   however , localized herpes zoster is the most frequent clinical presentation in adult patients after cbt .
in addition to localized herpes zoster , a rare occurrence of vzv reinfection manifesting as a generalized vesicular eruption without herpes zoster lesions , as was seen in our patient , has been previously observed in patients after cbt .
this type of vzv reinfection can be caused by either reactivation of latent virus or exogenous reinfection with vzv .
since we did not compare vzv dna between the primary and present infection , it remains unknown whether the infection in our patient was of exogenous or endogenous origin .
anti - vzv igg has anti - vzv activity and remains in the body for a long time .
considering that our patient had a childhood history of varicella and that the serum anti - vzv igg at day 3 was negative , it appears that humoral immunity against vzv had been lost after cbt , resulting in susceptibility to vzv reinfection . in general , vzv reinfection that appears clinically to be varicella follows a mild clinical course in normal elderly people and immunocompromised hosts .
this may be partly explained by the lack of anti - vzv igg at the onset of the skin eruption .
however , aisa et al . have reported a case of post - cbt varicella with a relatively severe clinical course despite the presence of a high anti - vzv igg titer .
further investigations are necessary to determine why certain post - cbt patients develop varicella , and to clarify why vzv reinfection in post - cbt patients may be more severe than that in normal aged people and immunocompromised patients .
 most varicella - zoster virus ( vzv ) infections after cord blood transplantation ( cbt ) present as localized herpes zoster . here 
 , we report a case of vzv reinfection in an adult patient after cbt that appeared clinically to be varicella . 
 a 50-year - old japanese man underwent cbt for the management of acute lymphoblastic leukemia . 
 seventeen months later , he developed a small number of vesicles with umbilicated centers . 
 a skin biopsy showed an intraepidermal blister containing degenerated balloon cells . 
 subsequently , the skin eruption developed over his entire body . 
 the patient was treated with intravenous acyclovir for 5 days , followed by oral valacyclovir for 9 days . 
 it took more than 3 weeks for most of the skin lesions to scab . 
 serum levels of anti - vzv igg on days 3 and 33 after the onset of the skin eruption were negative and 260 miu / ml , respectively . 
 serum anti - vzv igm on days 3 and 33 was not detected . 
 our patient was diagnosed with vzv reinfection . 
Introduction
Case Report
Discussion