Last week, Dr. Rohini Handa presented a case challenge about a patient who presented with purpura and opened up the forum to interpretation. You gave us your responses and this week, we bring you the evaluation from our expert. In this article, Dr. Rohini Handa provides the right responses to each question along with supporting points.

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Recap to the case*

Mrs MD, a 41-year-old lady, was referred with complaints of arthralgias and intermittent skin rash for 8-9 years. The rash was non-itchy and usually occurred on the legs and thighs (check figure). The arms and face were spared.

Prolonged standing in the kitchen aggravated the rash. There was no history of fever, weight loss, or anorexia. The patient denied any bleeding from the nose, mouth, ears or excessive bleeding during her periods. She was normotensive and non-diabetic. Physical examination was unremarkable except for palpable purpura on her legs (check figure). Heart/Chest NAD. No organomegaly was appreciated on abdominal examination. The joint examination did not reveal any synovitis or deformities.

*To read the full case click here

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Mrs MD has presented with purpura. Purpura is a non-blanchable rash caused by a bleed into the skin and mucosal membranes. Based on the size, skin haemorrhage may be classified into petechiae (1-3 mm), purpura (4-10 mm), or ecchymosis (>10 mm).

On the bedside, it is important to check if the purpura is flat and macular (non-palpable) or palpable. This helps in the differential diagnosis. Generally, non-palpable purpura is seen in bleeding or clotting disorders while palpable purpura is seen with an inflammatory vascular insult (leukocytoclastic vasculitis). Palpable purpura may be idiopathic, drug-induced, infection-induced, or part of autoimmune rheumatic diseases (ARDs).

Palpable purpura is especially noticeable on dependent areas like the legs or pressure-bearing surfaces like buttocks. Bleeding from orifices is not seen and is an important distinguishing feature from haematological causes which may be associated with bleeding from the oral cavity, nose, gastrointestinal or genitourinary tract, and intracranial bleed.

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The following are the answers to the case study questions

Question 1. What is the likely diagnosis?

Answer: Mrs. MD has a long-standing history of purpura which is palpable. The palpable nature of purpura and a normal platelet count rules out ITP. The duration of 8 to 9 years and absence of fever makes infections like infective endocarditis, meningococcemia and gonococcemia less likely. The absence of drug history is an important negative point. The presence of high ESR, rheumatoid factor and ANA point towards an autoimmune rheumatic disease.

Amongst the ARDs, the presence of RF and ANA argue against the diagnosis of Henoch Schonlein purpura (HSP) and the ANCA associated vasculitides [Microscopic polyarteritis, Granulomatosis with polyangiitis (Wegener’s granulomatosis) and Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)].

Patients with HSP do not demonstrate autoantibodies while the notable autoantibody in ANCA associated vasculitis (AAV) is ANCA. RF may be present in AAV. However, high titres of ANA, as in this case, are not seen in AAV. Rheumatoid arthritis is associated with purpura only in the setting of rheumatoid vasculitis.

The patient’s joint examination was remarkable for the absence of deformities and/or synovitis. This makes RA unlikely. The two likely ARDs based on the serologic profile of RF and ANA positivity are SLE and Sjogren’s syndrome. The absence of fever, lack of photosensitivity, and non-malar location of the rash are strong pointers against lupus. The typical rash of lupus occurs in sun-exposed areas. Sjogren’s syndrome can be pauci-symptomatic in many patients leading to delayed diagnosis.

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Question 2. What further investigations would you order?

Answer: Hepatitis and HIV serologies should be obtained to rule out hepatitis B, C or HIV. Ultrasound doppler and bone marrow examination are not likely to add to the diagnosis in this setting. A skin biopsy, while confirming leukocytoclastic vasculitis, is unlikely to shed light on aetiology or help guide treatment.

We ordered ANCA, dsDNA, and antibodies to extractable nuclear antigens (ENA). ANCA and dsDNA were negative. ENA demonstrated strongly positive Ro and La confirming Sjogren’s syndrome. On subsequent questioning, the patient denied sicca symptoms. Ophthalmic examination, however, revealed a positive Schirmer test and the presence of dry eyes.

Final diagnosis: Sjogren’s Syndrome

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Question 3: How would you treat her?

Answer: The patient was started on hydroxychloroquine and lubricant eye drops. She was counselled about the need for meticulous dental hygiene. In absence of significant neuropathy, kidney or lung involvement, corticosteroids are not indicated at the present time. She may need methotrexate if the joint symptoms do not adequately respond to hydroxychloroquine.

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Suggested reading

1. Stevens GL, Adelman HM, Wallach PM. Palpable purpura: an algorithmic approach. Am Fam Physician 1995; 52:1355-62.

2. Handa R. Clinical Rheumatology. Springer, 2021. https://www.springer.com/gp/book/9789813348844

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The two lucky winners of this challenge have been selected and will win Dr. Rohini Handa's latest book copy of Clinical Rheumatology. 

Disclaimer- The views and opinions expressed in this article are those of the author and do not necessarily reflect the official policy or position of M3 India.

The author, Dr. Rohini Handa is a Senior Consultant Rheumatologist from Delhi.