Open Digital Library of Pediatric Rheumatic Disease

Differential diagnosis of cutaneous vasculitis

 

Michael L. Miller and Kelly Rouster-Stevens

Division of Immunology and Rheumatology

Department of Pediatrics

Feinberg School of Medicine

Northwestern University, Chicago, IL

e-mail millermd@northwestern.edu

 

INTRODUCTION

            We continue our presentation of case-based learning.  This month, we present two patients with episodic fevers and rash. 

           

CASE 1.  A child with fevers, joint swelling, and rash is presented.  Students and residents may be asked what studies they would next obtain, and why (in terms of differential diagnosis).

 

An 8 month old boy presented with a 2 week history of nasal congestion and rhinorrhea, and a 3 day history of rash and fevers as high as 39oC.  A rash began as erythematous macules of the right calf associated with mild calf swelling.  Over the next two days, the lesions spread to his trunk and all extremities.  He has been on no medications recently.  The physical exam revealed an irritable infant, temp 39.7oC, normal HR, BP. The skin exam revealed diffuse purpuric lesions which had become coalescent in areas.  The palms and soles were edematous with sparing of the rash. The musculoskeletal exam showed full range of motion of all joints, with pain on flexion of bilateral knees and ankles. No joint swelling was seen.  Laboratory evaluation demonstrated an unremarkable CBC, differential, lumbar puncture, urinalysis, and an elevated sedimentation rate of 41mm/hour. Over the next 2 days, fevers became low grade.  Blood, urine, and CSF cultures were negative.  The rash then spread to his face.  What is the differential diagnosis?
 
 

 



Figure 1.  A maculopapular rash with areas of confluence is noted over the arms; a similar rash is found over the legs. 

 

 

 

 

 

DISCUSSION: Further rheumatologic evaluation should include an autoantibody screen, a urinalysis and a skin biopsy.  The skin biopsy revealed leukocytoclastic vasculitis. A differential diagnosis of this rash (including HSP, SLE, dermatomyositis, cutaneous polyarteritis nodosa) can be discussed with students and residents.  Additionally, the differential diagnosis of a young child with fevers, skin rash, irritability and joint findings (e.g. viral syndromes, systemic onset arthritis, vasculitis) can be discussed.  The child’s fever and rash resolved without corticosteroids or other treatment, and an etiology for his illness was not found. One teaching point that is important to emphasize is that children with leukocytoclastic vasculitis (including HSP) who have no evidence of internal vasculitis and are improving clinically may not require any corticosteroid therapy.

 

 

 

 

 

 

 

 

 

 

 

CASE 2.  A child with episodic fevers and rash is presented.  This case is useful in discussing the differential of a very different rash in the context of a possible pediatric rheumatic disease, as well as pointing out the usefulness of a skin biopsy in making the diagnosis.

 

 

A 12 year old boy presents with a 4 month history of recurrent fevers associated with lesions of the lower extremities.  The rash begins as a purple circular macule which enlarges becoming tender, firm, and slightly raised.  The episodes last 10-14 days and there is no pattern.  He also complains of knee and ankle pain without swelling.  He denies any headache, abdominal pain, vomiting, diarrhea, weight loss, night sweats, oral ulcers, or fatigue.  Physical examination reveals a well-appearing boy, temp 38oC, normal HR, BP.  Skin exam reveals a right mid-thigh with a 10 cm diameter tender area, raised with purple discoloration centrally, and circumferential erythema. Musculoskeletal was normal.  Laboratory evaluation demonstrates an unremarkable CBC, differential, liver enzymes, urinalysis, ESR, ANA, and rheumatoid factor.  What is the next step in determining a diagnosis?

 
 
 

 

 

 

 

 

 


 

CASE DISCUSSION:  The photograph demonstrates this boy’s episodic rash.  The important teaching point is that a skin biopsy is important in evaluating vasculitis and ruling out other causes.  In this patient, the biopsy revealed panniculitis.  The location and lack of nodularity of this patient's lesion, as well as the detailed desciption of the biopsy,  were not compatible with a diagnosis of erythema nodosum (EN).  The differential diagnosis of panniculitis not consistent EN (including rheumatic diseases, such as systemic lupus erythematosus, discoid lupus erythematosus, juvenile dermatomyositis, polyarteritis nodosa, synovitis - but not classic juvenile rheumatoid arthritis, and other entities such as α1-anti-trypsin deficiency) can be discussed with students and residents. The importance of a skin biopsy to exclude panniculitis associated with subcutaneous T cell lymphoma can also be discussed.  As in Case 1, treatment (such as oral corticosteroids) will depend upon the severity, duration of lesions and the underlying disease.  The major potential complication of panniculitis is cutaneous ulceration with secondary infection.  This patient has not yet been diagnosed with an underlying disease and is still being evaluated.