
 sweet 's syndrome ( ss ) is characterized by fever , neutrophil leukocytosis , acute onset of skin lesions and histological findings of dense neutrophilic infiltrate without any evidence of primary vasculitis.skin lesions in idiopathic ss usually occur in a generalized distribution and respond very well to oral corticosteroids . 
 
sweet 's syndrome ( ss ) is characterized by fever , neutrophil leukocytosis , acute onset of skin lesions and histological findings of dense neutrophilic infiltrate without any evidence of primary vasculitis .
skin lesions in idiopathic ss usually occur in a generalized distribution and respond very well to oral corticosteroids .
sweet 's syndrome ( ss ) was first described by robert douglas sweet in 1964 .
the three main clinical types which are described include : classical or idiopathic ss , malignancy - associated or paraneoplastic ss , and drug - induced ss .
approximately 70% of cases are idiopathic and the paraneoplastic form is present in 10 - 20% associated predominantly with hematological malignancies such as acute myelogenous leukemia , myelodysplastic syndromes and lymphoma .
ss is characterized by fever , neutrophil leukocytosis , acute onset of skin lesions and histological findings of dense neutrophilic infiltrate without any evidence of primary vasculitis .
we report a case of classical ss in a middle aged lady with skin lesions distributed in photo - exposed areas having a typical histopathology with therapeutic response to oral corticosteroids .
a 40-year - old lady with unknown co - morbidities presented with a 10 days history of multiple red raised painful lesions over body .
lesions were initially noted over forearms and in the next 2 - 3 days , new lesions appeared over arms and back .
patient complained of increased pain and burning sensation in the lesions while working in sunlight .
associated mild to moderate grade fever , intermittent in nature was present for the same duration .
there was a history of malaise , pain over large joints , decreased appetite and redness of eyes .
no history of oral ulcers , weight loss or any drug intake prior to her symptoms was present .
dermatological examination revealed erythematous papules coalescing to form plaques with a pseudovesicular appearance over the extensor aspect of forearms and photo - exposed areas on back [ figures 1 and 2 ] .
there was a sharp cut - off between the lesions and the photo - protected areas , where there were absolutely no lesions [ figure 3 ] .
erythematous papules and plaques on extensors of forearm close up of skin lesions showing a pseudovesicular appearance skin lesions on back with complete sparing of the area covered by clothes ( blouse ) investigations revealed anemia with haemoglobin of 9.5 gms / dl , and neutrophilic leukocytosis with 86% neutrophils out of a total of 13,000/mm .
she had an esr of 36 mm fall in the first hour by the westergren 's technique .
extensive radiological , biochemical and hematological investigations did not reveal any underlying malignancy or any systemic association .
skin biopsy revealed edema of the papillary dermis along with a heavy neutrophilic infiltrate in the upper dermis .
furthermore , coalescing infiltrate of neutrophils in the lower dermis especially around blood vessels with absence of vasculitis was seen [ figure 4 ] .
there was evidence of endothelial swelling with few fragmented neutrophilic nuclei but no fibrinoid necrosis [ figure 5 ] .
she responded dramatically to a course of oral steroids in the form of prednisolone 40 mg / day and topical broad spectrum photo - protection . within seven days ,
her fever had subsided and within the next two weeks most of her skin lesions regressed .
histopathology of skin lesions revealing prominent upper dermal edema with a heavy neutrophilic infiltrate in the upper dermis and a coalescing infiltrate of neutrophils in the lower dermis especially around blood vessels with absence of vasculitis ( h and e , 10 ) close up of the heavy neutrophilic infiltrate with some endothelial swelling and fragmented neutrophilic nuclei but no fibrinoid necrosis ( h and e , 40 )
diagnostic criteria for classical ss includes : 
 abrupt onset of painful erythematous plaques or noduleshistopathologic evidence of a dense neutrophilic infiltrate without evidence of leukocytoclastic vasculitis . 
 
abrupt onset of painful erythematous plaques or nodules histopathologic evidence of a dense neutrophilic infiltrate without evidence of leukocytoclastic vasculitis . 

pyrexia > 38cassociation with an underlying hematologic or visceral malignancy , inflammatory disease , or pregnancy , or preceded by an upper respiratory or gastrointestinal infection or vaccinationexcellent response to treatment with systemic corticosteroids or potassium iodide.abnormal laboratory values at presentation ( three of four ) : erythrocyte sedimentation rate > 20 mm / hr ; positive c - reactive protein ; > 8,000 leukocytes ; > 70% neutrophils . 
 
association with an underlying hematologic or visceral malignancy , inflammatory disease , or pregnancy , or preceded by an upper respiratory or gastrointestinal infection or vaccination excellent response to treatment with systemic corticosteroids or potassium iodide .
abnormal laboratory values at presentation ( three of four ) : erythrocyte sedimentation rate > 20 mm / hr ; positive c - reactive protein ; > 8,000 leukocytes ; > 70% neutrophils . both major criteria and two of the four minor criteria
our patient met all , but one minor criterion and thus , is a case of classical ss .
many theories regarding the etiology of ss have been proposed , including mechanical irritation , infection , dysfunctional neutrophil chemotaxis and phagocytosis , hypersensitivity , and induction by granulocyte colony stimulating factor ( g - csf ) .
interleukin-6 ( il-6 ) may be elevated in ss , which may account for the clinical features of fever and pain , as well as the elevated acute - phase reactants .
the relationship between il-6 and g - csf which can cause sweet 's is unclear ; that is , do they rise in concert or does one stimulate production of the other ?
however , the triggering or aggravating role of uv radiation has not been mentioned as a major factor in literature .
the most frequently incriminated drug is g - csf ; others include all - trans retinoic acid , carbemazepine , celecoxib , diazepam , diclofenac , hydralazine , levonorgestrel with ethinyl estradiol , minocycline , nitrofurantoin , propylthiouracil , and trimethoprim - sulfamethoxazole .
pathergy may be positive in ss especially at sites of cutaneous trauma induced by skin biopsies , vaccination and venipuncture .
there are very few previous case reports describing the worsening of idiopathic sweet syndrome after sun exposure or photo distribution of lesions .
the pathomechanism could involve either an isomorphic koebner reaction , classically described in neutrophilic dermatoses , or the direct action of uv - b on neutrophil activation and recruitment in skin through the production of cytokines , such as interleukin 8 or tumor necrosis factor . other rare presentations of ss described include symmetrically distributed ulcerated and crusted plaques studded with bullae , lesions resembling pyoderma gangrenosum and cutis laxa following ss .
systemic glucocorticoids are the first line treatment for ss . systemic symptoms and cutaneous manifestations rapidly improve after starting therapy . our patient was treated with oral corticosteroids with a good response within few weeks .
many other treatments have been reported to be successful in ss , such as potassium iodide , colchicine , indomethacin , dapsone , doxycycline , cyclosporine , cyclophosphamide , chlorambucil and clofazimine . without treatment ,
ss lesions may persist for weeks or even months , or they may eventually resolve spontaneously .
our case highlights the concept that idiopathic ss can present as photo - dermatosis , though further investigations are required to find out the factors responsible for photo - aggravation .
this case emphasizes the need of a systematic search for prior sun exposure in sweet syndrome , especially in the so - called idiopathic forms . 

sweet 's syndrome can occur in a photodistributed pattern.sunlight can be a triggering factor for sweet 's syndrome and so photoprotection is important for this subset of patients . 
  sweet 's syndrome can occur in a photodistributed pattern .
sunlight can be a triggering factor for sweet 's syndrome and so photoprotection is important for this subset of patients .

 abrupt onset of painful erythematous plaques or noduleshistopathologic evidence of a dense neutrophilic infiltrate without evidence of leukocytoclastic vasculitis . 
 
abrupt onset of painful erythematous plaques or nodules histopathologic evidence of a dense neutrophilic infiltrate without evidence of leukocytoclastic vasculitis .

 pyrexia > 38cassociation with an underlying hematologic or visceral malignancy , inflammatory disease , or pregnancy , or preceded by an upper respiratory or gastrointestinal infection or vaccinationexcellent response to treatment with systemic corticosteroids or potassium iodide.abnormal laboratory values at presentation ( three of four ) : erythrocyte sedimentation rate > 20 mm / hr ; positive c - reactive protein ; > 8,000 leukocytes ; > 70% neutrophils . 
 
association with an underlying hematologic or visceral malignancy , inflammatory disease , or pregnancy , or preceded by an upper respiratory or gastrointestinal infection or vaccination excellent response to treatment with systemic corticosteroids or potassium iodide .
abnormal laboratory values at presentation ( three of four ) : erythrocyte sedimentation rate > 20 mm / hr ; positive c - reactive protein ; > 8,000 leukocytes ; > 70% neutrophils . both major criteria and two of the four minor criteria are required to establish the diagnosis of classical ss .
our patient met all , but one minor criterion and thus , is a case of classical ss .
many theories regarding the etiology of ss have been proposed , including mechanical irritation , infection , dysfunctional neutrophil chemotaxis and phagocytosis , hypersensitivity , and induction by granulocyte colony stimulating factor ( g - csf ) .
interleukin-6 ( il-6 ) may be elevated in ss , which may account for the clinical features of fever and pain , as well as the elevated acute - phase reactants .
the relationship between il-6 and g - csf which can cause sweet 's is unclear ; that is , do they rise in concert or does one stimulate production of the other ?
however , the triggering or aggravating role of uv radiation has not been mentioned as a major factor in literature .
the most frequently incriminated drug is g - csf ; others include all - trans retinoic acid , carbemazepine , celecoxib , diazepam , diclofenac , hydralazine , levonorgestrel with ethinyl estradiol , minocycline , nitrofurantoin , propylthiouracil , and trimethoprim - sulfamethoxazole .
pathergy may be positive in ss especially at sites of cutaneous trauma induced by skin biopsies , vaccination and venipuncture .
there are very few previous case reports describing the worsening of idiopathic sweet syndrome after sun exposure or photo distribution of lesions .
the pathomechanism could involve either an isomorphic koebner reaction , classically described in neutrophilic dermatoses , or the direct action of uv - b on neutrophil activation and recruitment in skin through the production of cytokines , such as interleukin 8 or tumor necrosis factor . other rare presentations of ss described include symmetrically distributed ulcerated and crusted plaques studded with bullae , lesions resembling pyoderma gangrenosum and cutis laxa following ss .
systemic glucocorticoids are the first line treatment for ss . systemic symptoms and cutaneous manifestations rapidly improve after starting therapy . our patient was treated with oral corticosteroids with a good response within few weeks .
many other treatments have been reported to be successful in ss , such as potassium iodide , colchicine , indomethacin , dapsone , doxycycline , cyclosporine , cyclophosphamide , chlorambucil and clofazimine . without treatment ,
ss lesions may persist for weeks or even months , or they may eventually resolve spontaneously .
our case highlights the concept that idiopathic ss can present as photo - dermatosis , though further investigations are required to find out the factors responsible for photo - aggravation .
this case emphasizes the need of a systematic search for prior sun exposure in sweet syndrome , especially in the so - called idiopathic forms . 

sweet 's syndrome can occur in a photodistributed pattern.sunlight can be a triggering factor for sweet 's syndrome and so photoprotection is important for this subset of patients . 
  sweet 's syndrome can occur in a photodistributed pattern .
sunlight can be a triggering factor for sweet 's syndrome and so photoprotection is important for this subset of patients .
 a 40-year - old lady presented with history of multiple red raised painful lesions over her body of 10 days duration . 
 lesions spread from forearms to arms and back of trunk during the progress of the disease . associated pain and burning sensation in the lesions was present while working in the sun . 
 mild to moderate grade fever , malaise , pain over large joints , decreased appetite , and redness of eyes was also present . 
 there was no history of drug intake or other risk - factors . 
 dermatological examination revealed erythematous papules coalescing to form plaques with a pseudovesicular appearance over the extensor aspect of forearms and photo - exposed areas on the back of trunk . 
 there was a sharp cut - off between the lesions and the photo - protected areas . 
 investigations revealed anemia , neutrophilic leukocytosis , raised erythrocyte sedimentation rate and positive c reactive protein . 
 skin biopsy showed characteristic features of sweet 's syndrome . 
 no evidence for any secondary etiology was found . 
 she responded to a tapering course of oral steroids and topical broad spectrum photo - protection . 
 this case is a very rare instance of idiopathic sweets syndrome occurring in a photo - distributed pattern . 
Introduction
Case Report
Discussion
Major criteria
Minor criteria