Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Nodular Lesions on the Arm—Diagnosis

Nodular Lesions on the Arm—Diagnosis Diagnosis: Lobomycosis. Microscopic findings and clinical course The lesional biopsy specimen revealed numerous and diffuse inflammatory granulomas in the dermis. The granulomas were composed of histiocytes and giant cells containing numerous phagocytosed thick-walled cells. An asteroid body was also seen. The GMS stain showed the typical yeasts of lobomycosis in chains of uniform round to oval cells. The nodules were completely excised, and the patient was given itraconazole, 200 mg/d, for 6 months as an attempt to prevent disease relapse. Discussion Lobomycosis, also known as Lobo disease, is a chronic fungal disease that affects the skin and subcutaneous tissue.1 It was first described in Brazil in 1931 by Jorge Lobo.2 The etiologic agent has been named, after much controversy, as Lacazia loboi.3 The disease affects people living in the tropical zone of the New World.2 It has been described mostly in Brazil,4 but it has also been found in Colombia, Surinam, Costa Rica, Venezuela, French Guiana, and Panama. The disease has also been described in dolphins.1 Lobomycosis mainly affects men, and it is most likely to be related to occupational exposure.2 The high-risk activities include farming, gold mining, fishing, and hunting.1 Patients often reported a bite or sting from an arthropod, snake, or stingray or otherwise trauma from a cutting instrument.2 The disease is clinically characterized by variably sized dermal nodules, either lenticular or in plaques. They can be either hypopigmented or hyperpigmented and occasionally achromic. Although any area of the body is potentially susceptible, since infection usually follows trauma,2 the most commonly affected areas include the lower extremities, the ears, and the upper extremities.4 Differential diagnosis includes leprosy, anergic cutaneous leishmaniasis, chromoblastomycosis, paracoccidioidomycosis, Kaposi’s sarcoma, keloids, fibroma, neurofibromas, dermatofibrosarcoma protuberans, and metastatic lesions.1,2 Diagnosis may be established by skin smear or biopsy.4 Skin smear allows direct visualization of the parasite. Lobomyces are yeastlike, rounded, thick-walled cells that occur in chains of 2 to 10 cells.2 Histopathologic features are pathognomonic. The epidermis is usually atrophic and the dermis is occupied by a fibrous, diffuse, inflammatory granuloma composed of histiocytes and giant cells containing the typical thick-walled cells. Asteroid bodies may also be seen in lobomycosis; they are intracytoplasmic eosinophilic star-shaped structures also seen in sarcoidosis, tuberculosis, and other mycosis. Periodic acid–Schiff, GMS, or Gridley silver stains clearly distinguish the yeastlike cells.1,2,4Lacazia loboi has not been cultured in vitro.3 The optimal treatment for localized lesions is wide surgical excision, ensuring that margins are free of infection to avoid recurrence. Disseminated lesions are better treated with chemotherapy.2 Clofazimine,4 itraconazole, and a combination of both drugs have been successfully used in a few cases.5 References 1. Brun AM Lobomycosis in three Venezuelan patients. Int J Dermatol 1999;38 (4) 302- 305PubMedGoogle ScholarCrossref 2. Talhari SPradinaud R Topley & Wilson's Microbiology and Microbial Infections: Medical Mycology. Washington, DC Edward Arnold Ltd2005;430- 435 3. Taborda PRTaborda VAMcGinnis MR Lacazia loboi gen. nov., comb. nov., the etiologic agent of lobomycosis. J Clin Microbiol 1999;37 (6) 2031- 2033PubMedGoogle Scholar 4. Talhari SSouza MDGMendes APTalhari A Deep mycoses in Amazon region. Int J Dermatol 1988;27 (7) 481- 484PubMedGoogle ScholarCrossref 5. Fischer MChrusciak Talhari AReinel DTalhari S Successful treatment with clofazimine and itraconazole in a 46 year old patient after 32 years duration of disease. Hautarzt 2002;53 (10) 677- 681PubMedGoogle ScholarCrossref http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Archives of Dermatology American Medical Association

Nodular Lesions on the Arm—Diagnosis

Archives of Dermatology , Volume 143 (10) – Oct 1, 2007

Nodular Lesions on the Arm—Diagnosis

Abstract

Diagnosis: Lobomycosis. Microscopic findings and clinical course The lesional biopsy specimen revealed numerous and diffuse inflammatory granulomas in the dermis. The granulomas were composed of histiocytes and giant cells containing numerous phagocytosed thick-walled cells. An asteroid body was also seen. The GMS stain showed the typical yeasts of lobomycosis in chains of uniform round to oval cells. The nodules were completely excised, and the patient was given itraconazole, 200 mg/d, for 6...
Loading next page...
 
/lp/american-medical-association/nodular-lesions-on-the-arm-diagnosis-E5MqIABMiI
Publisher
American Medical Association
Copyright
Copyright © 2007 American Medical Association. All Rights Reserved.
ISSN
0003-987X
eISSN
1538-3652
DOI
10.1001/archderm.143.10.1323-g
Publisher site
See Article on Publisher Site

Abstract

Diagnosis: Lobomycosis. Microscopic findings and clinical course The lesional biopsy specimen revealed numerous and diffuse inflammatory granulomas in the dermis. The granulomas were composed of histiocytes and giant cells containing numerous phagocytosed thick-walled cells. An asteroid body was also seen. The GMS stain showed the typical yeasts of lobomycosis in chains of uniform round to oval cells. The nodules were completely excised, and the patient was given itraconazole, 200 mg/d, for 6 months as an attempt to prevent disease relapse. Discussion Lobomycosis, also known as Lobo disease, is a chronic fungal disease that affects the skin and subcutaneous tissue.1 It was first described in Brazil in 1931 by Jorge Lobo.2 The etiologic agent has been named, after much controversy, as Lacazia loboi.3 The disease affects people living in the tropical zone of the New World.2 It has been described mostly in Brazil,4 but it has also been found in Colombia, Surinam, Costa Rica, Venezuela, French Guiana, and Panama. The disease has also been described in dolphins.1 Lobomycosis mainly affects men, and it is most likely to be related to occupational exposure.2 The high-risk activities include farming, gold mining, fishing, and hunting.1 Patients often reported a bite or sting from an arthropod, snake, or stingray or otherwise trauma from a cutting instrument.2 The disease is clinically characterized by variably sized dermal nodules, either lenticular or in plaques. They can be either hypopigmented or hyperpigmented and occasionally achromic. Although any area of the body is potentially susceptible, since infection usually follows trauma,2 the most commonly affected areas include the lower extremities, the ears, and the upper extremities.4 Differential diagnosis includes leprosy, anergic cutaneous leishmaniasis, chromoblastomycosis, paracoccidioidomycosis, Kaposi’s sarcoma, keloids, fibroma, neurofibromas, dermatofibrosarcoma protuberans, and metastatic lesions.1,2 Diagnosis may be established by skin smear or biopsy.4 Skin smear allows direct visualization of the parasite. Lobomyces are yeastlike, rounded, thick-walled cells that occur in chains of 2 to 10 cells.2 Histopathologic features are pathognomonic. The epidermis is usually atrophic and the dermis is occupied by a fibrous, diffuse, inflammatory granuloma composed of histiocytes and giant cells containing the typical thick-walled cells. Asteroid bodies may also be seen in lobomycosis; they are intracytoplasmic eosinophilic star-shaped structures also seen in sarcoidosis, tuberculosis, and other mycosis. Periodic acid–Schiff, GMS, or Gridley silver stains clearly distinguish the yeastlike cells.1,2,4Lacazia loboi has not been cultured in vitro.3 The optimal treatment for localized lesions is wide surgical excision, ensuring that margins are free of infection to avoid recurrence. Disseminated lesions are better treated with chemotherapy.2 Clofazimine,4 itraconazole, and a combination of both drugs have been successfully used in a few cases.5 References 1. Brun AM Lobomycosis in three Venezuelan patients. Int J Dermatol 1999;38 (4) 302- 305PubMedGoogle ScholarCrossref 2. Talhari SPradinaud R Topley & Wilson's Microbiology and Microbial Infections: Medical Mycology. Washington, DC Edward Arnold Ltd2005;430- 435 3. Taborda PRTaborda VAMcGinnis MR Lacazia loboi gen. nov., comb. nov., the etiologic agent of lobomycosis. J Clin Microbiol 1999;37 (6) 2031- 2033PubMedGoogle Scholar 4. Talhari SSouza MDGMendes APTalhari A Deep mycoses in Amazon region. Int J Dermatol 1988;27 (7) 481- 484PubMedGoogle ScholarCrossref 5. Fischer MChrusciak Talhari AReinel DTalhari S Successful treatment with clofazimine and itraconazole in a 46 year old patient after 32 years duration of disease. Hautarzt 2002;53 (10) 677- 681PubMedGoogle ScholarCrossref

Journal

Archives of DermatologyAmerican Medical Association

Published: Oct 1, 2007

References