Bacillary angiomatosis in an immune-competent patient

Introduction

Bacillary angiomatosis (BA)- a recently de-scribed entity caused by a rickettsia, is a rare disor-der characterised by angiomatous lesion in the skin, mucosa and internal organs. BA is mostly associ-ated with acquired immunodeficiency syndrome (AIDS), rarely with other immunodeficient states and very rarely in healthy person.[1] BA is rarely reported in Indian literatures. Here is a report of such a very rare case.

Case Report

An elderly person of 65 years, business- man by profession presented with multiple erythematous, nonpruritic, papular and plaque type of eruptions over the extensor aspect of the right forearm for the last two months. The patient was otherwise alright and denied history of exposure or homosexuality, nor he was on any immunosuppressive drugs. Ex-amination revealed around ten reddish brown pap-ules and plaques of varying sizes-1.5 cm to 2.5 cm in diameter distributed over the forearm in a linear fashion. The lesions blanched partially on diascopy. There was no mucous membrane lesion, no lymphad-enopathy, or hepato- splenomegaly. Routine blood test and urinalysis showed no abnormality. Erythro-cyte sedimentation rate was 20mm 1st hour. Blood sugar was 130mg. (post prandial). Chest x-ray and ultrasound study of abdomen did not reveal any pa-thology. Liver biopsy was not done due to inherent risk of bleeding from the angiomatous lesion, if present. Mantoux test was positive. Serum IgG was 850 mg/dl. (normal 723-1685). Serum 1gM was 120 mg/d1. (normal 60-263 mg/d1) by Rate nephlometric principle. VDRL test and ELISA tests for HIV were negative. Histology showed neovascularisation in the upper dermis. The endothelial cells of the capillaries were enlarged with clear cytoplasm giving it an appearance of epitheloid cell. There was no cellular atypia. There was not much inflammatory infiltrate nor any accumulation of eosinophils. The patient was put on a course of erythromycin (500 mg.) four times daily. The lesions disappeared completely in a course of 15 days. Identification of the causative bacillus could not be done due to lack of laboratory facility.

Discussion

BA is rather a new entry in medical vocabu-lary. It was first described by Stoler et al in 1983, in an AIDS patient with multiple subcutaneous tumours accompanied by fever, sweating and weight loss.[2] Later on Cockrell et al reported similar cases.[2] Their patients in addition to skin lesions had lesions in the liver and bone. Initial epidemiological and histopatho-logical data suggested that the causative agent of BA is the cat scratch disease bacillus. But the lack of associated cat contact, different clinical pattern and the response to erythromycin suggest that the bac-teria are not identical. A gram negative bacillus-

Rochalimaca henselae - is the bacillus recently recognised as the causative agent of BA. This bacil-lus is demonstrated by a special stain called Warthen--Starry stain and by electron microscopic study where it appears as bacillary form with a trilamillar cell wall. The diagnosis in this particular patient was made from the unique clinical features and histological find-ings of neo-vascularisation in an elderly person and the therapeutic response to erythromycin. The most common risk factor for BA is HIV infection. This par-ticular case reported herein is one of those very few patients of BA where the person is competent immunologically.