Eosinophilic leukemoid reaction in a case of bullous pemphigoid

Prafulla Kumar Sharma, Namitha Rath, Suresh Kumar Sharma, Ram Krishan Gautham, Hemant Kumar Kar

 Department of Dermatology, Dr. RML Hospital, New Delhi-110 001, India

Correspondence Address:
Prafulla Kumar Sharma
E-4, CGHS Dispensary, Dr Zakir Hussain Marg, Pandara Park, New Delhi- 110003
India

Introduction

Bullous pemphigoid is a disease of the elderly, characterised clinically at the start with urticaria-like and pruritic erythematous lesions and later by large tense bullae. Eosinophilic Ieukemoid reactions are often seen in parasitic, allergic, neoplastic, collagen vascular diseases and drug reactions.[1],[2] Eosinophilia in blood has been reported in bullous pemphigoid previously[3] but an eosinophilic Ieukemoid reaction seen in our case is exceptional. We herein report such a case who has eosinophilic leukemoid reaction.

Case Report

A 70-year-old woman was admitted with pruritus, urticarial plaques followed by large tense bullae (10-20 mm) for the last 10 days. These bullae were present over erythematous base having clear fluid in some and haemorrhagic in others. The biopsy from urticarial plaque revealed a sub-epidermal cleft with eosinophils at the tip of papillae. The dermis showed infiltrate consisting mainly of eosinophils with few neutrophils and lymphocytes. There was no clinical evidence of malignancy of the genito-urinary tract and of colon on colonoscopy. Pap smear from cervix was free of malignant cells. On ultrasound of abdomen, liver, gall-bladder, kidneys and pelvis were normal.

The haemoglobin was 11 g% and the total leucocyte count was 28, 700/mm,3 eosinophils 72% and absolute eosinophil count 21, 660/mm2 (normal 52-250mm3). Platelet count was 362, 000/mm3. No immature cells were present in the peripheral blood smear. The bone marrow aspiration revealed mild eosinophilic proliferation with shift towards immaturity. Few eosinophilic myelocytes were also seen in the aspiration. The blood biochemistry was normal.

On commencing 60mg prednisolone orally, the weekly total leucocyte count was observed to be 10,000/mm3, 5600/mm3 respectively. Eosinophil percentage and absolute eosinophil count fell to 46, 18 and 01 and 4650/mm3, 1250/mm3 and 60/mm3 respectively. During three week period the lesions of bullous pemphigoid had healed and the prednisolone dose was reduced to 40 mg per clay.

Discussion

A leukemoid reaction of blood picture is one in which the peripheral blood findings resemble those found in leukemia with the important difference that while leukemia is a neoplastic proliferation, leukemoid reactions are benign proliferations.[4] There is no absolute criteria for differentiation between leucocytosis and leukemoid reactions. We considered this patient as having eosinophilic leukemoid reaction[1] primarily because of leucocytosis, very high eosinophil count (absolute eosinophil count 21,650/mm2) and bone marrow aspiration showing eosinophilic proliferation and few eosinophilic myelocytes. Leucocyte alkaline phosphatase was not done as eosinophils do not contain alkaline phosphatase. Leukemoid reactions are always a secondary phenomenon and as the cause is removed or cured, the reactions subside as happened in our patient.

Inflammatory and chemotactic factors for eosinophils, identified in blisters, may have some role in the blister formation.[6] In our case, the biopsy from the lesion, mainly showed the eosinophilic infiltration. So, these factors either directly or indirectly could be responsible for bone marrow eosinophilic reaction and eosinophilic leukemoid blood picture. Eosinophilic leukemoid reaction is likely to occur in patients of bullous pemphigoid who present with urticarial plaques and predominant eosinophilic dermal infiltrate.

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