Sporotrichoid pattern of cutaneous nocardiosis

AC Inamadar, A Palit

 Department of Dermatology, Venereology & Leprology, BLDEA’S SBMP Medical College, Hospital & Research Centre, Bijapur, Karnataka, India

Correspondence Address:
A C Inamadar
Department of Dermatology, Venereology & Leprology, BLDEA’S SBMP Medical College, Hospital & Research Centre, Bijapur, Karnataka
India

Introduction

Nocardia species is known to infect different organ systems of human body including skin.[1] Since there is no distinctive clinical feature for this infection, it is easily misdiagnosed unless high level of clinical suspicion is employed. Cutaneous nocardiosis occuring in sporotrichoid pattern is relatively rare,[2] and countable cases are reported worldwide till date.[2] Here we describe a young male patient with nodular lymphangitis of lower extremity caused by nocardia species.

Case Report

A 16 years old male patient presented with multiple linearly arranged nodular lesions over right lower extremity. It started over the dorsum of foot as a small solitary painful nodule following a botanical injury 3 months back. On clinical examination, firm, tender, nodular lesions of 1.5-2.5 cm were seen arranged in a line, extending from dorsum of right foot to the front of the leg. The intervening skin between the nodules was erythematous with palpable cordlike structures. Some of the nodules were suppurative and one had a verrucous surface. There was no sinus or discharge of granules from the lesions. Inguinal lymph nodes on right side were palpable and tender.

Routine haematological, biochemical and radiological examinations were within normal limits. Gram stain and modified AFB stain of the aspirated material from a suppurative lesion showed thin branching filaments KOH preparation was negative for any fungal elements. Culture on Sabourad′s agar media did not grow specific organism. Skin biopsy was taken from a nodule and on histopathological examination by H&E stain, it showed granulomatous changes with inflammatory infiltrate in the dermis. Organisms were not demonstrable in the tissue section.

We made a diagnosis of lymphocutaneous nocardiosis and started treatment with Cotrimoxazole DS tablets, twice daily. Clinical improvement was observed within 15 days and there was complete resolution of the lesions after 3 months of therapy. Treatment was continued for further 3 months after clinical resolution.

Discussion

Primary cutaneous nocardiosis can occur in acute or chronic forms.[3] The chronic form, mycetoma is much commoner than the acute form. Acute cutaneous nocardial infections, also known as superficial nocardial skin infections, present as pustules, abscess or features of cellulitis.[1],[2] In only one third[4] of these cases there is a spread through the lymphatics to the regional lymph nodes, giving rise to lymphocutaneous type.

Soil being the inhabitance of these organisms, primary inoculation by minor injuries like thorn prick, is the usual source of infection.[1] Insect bite and cat scratch are also reported as initiating factors.[5] Extremities are the common site of initial infection and it usually starts as a chancre at the site of inoculation, followed by development of chains of nodules extending proximally.[1],[2]

Nocardia brasiliensis is the most frequently isolated organism form lymphocutaneous variety.[1],[5] It is a highly virulent organism in laboratory animals because of the production of extracellular proteases.[2] Such pattern of infection can also be caused by Nocardia asteroides[5] and Nocardia caviae.[2] Isolation of the species was not possible in our patient. From animal experiments, it is evident that cell mediated immunity plays the pivotal role in host response to nocardia infection.[2] There is macrophage activation and induction of a T cell population capable of direct lymphocyte mediated toxicity to nocardia.[2]

Linear nodular lymphangitic lesion[6] is classically seen in sporotrichosis, caused by a dimorphic fungi, Sporothrix schenckil. Hence it has acquired a special name, the sporotrichoid pattern. However, sporotrichoid lesions can also be caused by Nocardia species,[1],[2],[3],[4],[5] Leishmania brasiliensis,[7],[8] and atypical mycobacteria (M.marinum & M.chelonae).[7] Uncommonly it can be caused by pyogenic bacteria,[9] like Streptococcus pyogenes and Staphylococcus aureus, and deep fungal infections,[7] like primary inoculation forms of blastomycosis, cocoidomycosis, cryptococcosis and histoplasmosis. Rarely, a malignant disease, epithelioid sarcoma,[10] may assume sporotrichoid pattern. Lymphocutaneous nocardiosis is more acute in onset and clinical course of the disease is more inflammatory than sporotrichosis.[2] In contrast to mycetoma, sulphur granules are absent in this variety of disease.[2] Other condition have to be differentiated by careful history, areas of endemicity, laboratory tests, histopathological examination and therapeutic trial.

Nocardia is a slow growing organism and may be difficult to grow from clinical specimens, because other rapidly growing bacteria easily obscure small nocardial colonies.11 Unfortunately, we could not isolate the species of nocardia causing infection in our patient. However, microscopical demonstration of typical morphology of the organism, histopathological evidence of granuloma, and dramatic therapeutic response to cotrimoxazole helped to confirm our clinical impression.

1.	Odom RB, James WD, Berger TG.Diseases resulting form fungi and yeasts. In: Andrews' Diseases of the skin, clinical dermatology,9th edn, Philadelphia: W.B Saunders company, 2000:p 411-412. [Google Scholar]
2.	Yang, LJ, Chan HL, Chen WJ, Kuo TT. Lymphocutaneous nocardiosis caused by Nocardia caviae: The first case reported from Asia. J Am Acad Dermatol 1993; 29:639-641. [Google Scholar]
3.	Angelika J. Primary cutaneous nocardiosis in a husband and wife J Am Acad Dermatol 1999; 41:338 [Google Scholar]
4.	Mc Neil MM, Brown JM. The medically important actinomycetes: epidemiology and microbiology. Clin Microbiol Rev 1994; 7:357-417. [Google Scholar]
5.	Kannon GA, Kuechle MK, Garrett AB. Superficial cutaneous Nocardia asteroides infection in an immunocompetent pregnant woman.J Am Acad Dermatol 1996; 35(6):1000-2. [Google Scholar]
6.	Kostman JR, DiNubile MJ.Nodular lymphangitis:a distinctive but often unrecognised syndrome.Ann Intern Med.1993; 118:883-888. [Google Scholar]
7.	Johnson MM, Meier MP.A palmar chancre and multiple proximal erythematous nodules.Arch Dermatol 1996; 132:963-968. [Google Scholar]
8.	Spier S,Medenica M, McMillian S, Virtue C.Sporotrichoid leishmaniasis.Arch Dermatol. 1977; 113:1104-1105. [Google Scholar]
9.	Tanaka S, Mochizuki T, Watanabe S.Sporotrichoid pyogenic bacterial infection. Dermatologica.1989; 178:228-230. [Google Scholar]
10.	Santiago H,Feinerman LK, lattes R.Epithelioid sarcoma : a clinical and parthologic study of nine cases. Hum Pathol 1972; 3:133-147. [Google Scholar]
11.	Lerner PI. Nocardiosis. Clin Infect Dis 1996 ; 22:891-903. [Google Scholar]