henoch  schonlein purpura ( hsp ) is an immune complex mediated small vessel vasculitis involving iga deposition in the capillaries of the kidney , skin , and gastrointestinal tract .
medications , vaccinations , infections , tumors , and insect bites have been mentioned as causes of hsp .
we report a rare case of hsp following an insect bite in a 26-year - old woman , who , in succession , had a nodular rash on the elbows , erythema nodosum , and palpable purpura .
a 26-year - old farm laborer presented to our outpatient department ( opd ) with a nodular rash that had developed on both elbows [ figure 1a and b ] following an insect bite while she sleeping .
she had pruritus over the affected areas and her lower limbs as well , but without any rash [ figure 1c ] .
two days later , she presented to the opd with complaints of tender and erythematous nodules on the legs [ figure 1d ] .
her investigations revealed the following : hemoglobin 10.9 g / dl , total leukocyte count 10.6  10/l with 76% neutrophilia , erythrocyte sedimentation rate 40 mm / h , urea 9.94 mmol / l , creatinine 44 mol / l , platelets 284  10/l , and 40 - 50 rbcs / hpf on urinalysis without proteinuria .
she was unwilling to be admitted and was , therefore , sent home and was prescribed acetaminophen and chlorpheniramine .
she came back 1 week later with a purpuric rash on her lower limbs [ figure 1e ] , diffuse abdominal pain , and arthralgias of the knees , ankles , and elbows .
examination showed non - palpable purpura , pedal edema , tender peri - umbilical region , and an otherwise normal systemic examination .
her urea and creatinine were 12.07 mmol / l and 52.8 mol / l , respectively .
her electrocardiogram and liver function tests were normal , while ultrasonogram showed minimal free fluid in the pelvis .
her immunological profile was as follows : rheumatoid factor negative , antistreptolysin o ( aso ) titer < 200 iu , antinuclear antibody 0.6 u ( < 1.0 u ) , complement c3 0.94
testing for cytoplasmic- antineutrophil cytoplasmic antibodies ( c - anca ) could not be done since the patient refused to undergo any further investigations .
she was initiated on methylprednisolone 8 mg daily , ranitidine , and hydroxyzine , and over the next 3 days , her signs gradually subsided .
( a , b ) nodular rash around the left and right elbows developed few hours after the insect bite ; ( c ) absence of any rash in the lower limbs during the first visit ; ( d ) erythema nodosum bilaterally 48 h after the first visit ; ( e ) purpuric rash in both lower limbs 1 week after the second visit
vasculitic disorders are classified according to whether the small , medium , or large arteries are involved .
hsp , urticarial vasculitis , cryoglobulinemic vasculitis , and cutaneous small vessel vasculitis are referred to as small vessel vasculitides .
johann lukas schonlein and his pupil edouard heinrich henoch contributed to the recognition of this entity .
adults may or may not have more severe kidney disease depending upon the series studied . the capillaries , post - capillary venules , and non - muscular arterioles are inflamed .
many viruses and bacteria have been implicated , but in the majority of cases , none have been found .
barr virus , and vaccinations related to measles and enteric fever have been reported as etiologies .
abnormalities in hsp include dysregulation of interleukin ( il)-1 homoeostasis and homozygous and heterozygous mutations of mediterranean fever ( mefv ) gene that is involved in caspase-1 activation .
disease susceptibility arises from particular human leukocyte antigen ( hla ) types which influence iga function and/or clearance or those influencing immunomodulation .
features in descending order of frequency are purpura , arthritis , abdominal pain , nephritis , and gastrointestinal bleeding . also , 40 - 50% patients have renal involvement in the form of either hematuria or proteinuria
nodules as a manifestation of vasculitis are more common with medium vessel vasculitides , whereas purpura , papules , vesicles , and urticaria are commoner with small vessel vasculitides .
our patient had a nodular rash at onset , a feature which had not been previously described .
subcutaneous nodules can be seen in hsp , but are more common in other conditions such as rheumatoid arthritis ( ra ) , systemic lupus erythematosus ( sle ) , and rheumatic fever .
these subcutaneous nodules , as in ra , develop at pressure sites like the elbow , as was seen in our patient .
erythema nodosum has been reported in only one instance of hsp and that too in a child .
this occurred 2 weeks prior to purpura and improved with clarithromycin that was administered for mycoplasma pneumoniae infection .
sequential development of three morphological patterns ( erythema nodosum , erythema marginatum , and purpura ) of rash was described in this child .
this is only the second account of a similar case with three different patterns of rash occurring in succession and the first in which a nodular rash is a precursor of hsp .
tissue biopsies are useful when the presentation is atypical . but in our case , the patient refused biopsies on two occasions .
other manifestations involve the heart , liver , lung , nervous system , pancreas , and adrenals .
systemic lupus , disseminated intravascular coagulation , and septicemia should then be considered in the differential diagnosis .
based on the hsp eular / printo / pres ankara 2008 classification , our patient had 3/4 criteria of the optional criteria .
the disease generally lasts for less than a month , with half of the patients having at least one recurrence , usually milder .
about 45 - 80% of adults can have renal involvement , and the risk of progression to chronic kidney disease is 30% . in conclusion , we have described here a unique sequential pattern of rashes in hsp occurring after an insect bite that improved with steroids .
clinicians must be aware that hsp may present with several patterns of rashes in succession . also , nodular rash and erythema nodosum could precede typical purpuric lesions in hsp .
 we describe a 26-year - old woman who presented with a nodular rash on the elbows following an insect bite . 
 two days later , she developed erythema nodosum . 
 both these lesions were treated symptomatically . 
 one week later , she had purpura , abdominal pain , hematuria , and arthralgias , following which steroids were administered . 
 her investigations revealed only microscopic hematuria that disappeared with therapy . 
 this pattern of sequential appearance of rash and a nodular morphology are both unique features not previously reported . 
INTRODUCTION
CASE REPORT
DISCUSSION