Journal of Dermatology 2015; 42: 267–268
doi: 10.1111/1346-8138.12788
LETTER TO THE EDITOR
Primary cutaneous mucormycosis caused by Mucor irregularis in an immunocompetent patient Dear Editor, Mucormycosis, which mainly affects immunocompromised patients, is a rare, life-threatening infection caused by the order Mucorales. Among the six clinical types of mucormycosis,1 cutaneous mucormycosis is the rarest and is further categorized into two types: (i) the gangrenous type, which only occurs in immunocompromised patients and progresses rapidly, and (ii) the superficial type, which develops in immunocompetent individuals, manifests as erythematous plaques, and progresses slowly.2 We present a case of superficial cutaneous mucormycosis caused by Mucor irregularis (M. irregularis) involving an immunocompetent patient. A 16-year-oldJapanese boy who was otherwise healthy presented with a 1-year history of a gradually enlarging plaque on his leg. A physical examination demonstrated an erythematous plaque exhibiting slight desquamation on his lower right leg, which he had scraped in a bicycle accident 2 years before (Fig. 1a). A histopathological examination detected a suppurative granuloma containing neutrophils, lymphocytes, and multinucleated giant cells in the dermis (Fig. 1b). Broad, ribbon-like, hyaline, aseptate hyphae were also observed (Fig. 1c). However, fungal hyphae and microvascular thrombosis were not detected in his blood vessels. Skin tissue specimens and skin scales cultured on Sabouraud dextrose agar at 25°C yielded wool-like, light yellow colonies, but no colony growth occurred at 38°C (Fig. 1d). Microscopic examinations of slide cultures detected sporangiophores, which had formed a terminal, globose sporangium. No apophyses were observed (Fig. 1e). These findings were consistent with Mucor fungi, and the isolate was identified as Mucor irregularis based on sequencing of the D1/D2 domain of the large subunit rRNA gene (GenBank accession no. IFM 57177). Before obtaining a diagnosis, we tried itraconazole (100 mg/ day), fluconazole (200 mg/day), and voriconazole (300 mg/day), independently, as empirical therapies, but none of them was effective. However, when we administered high-dose itraconazole (400 mg/day), the patient’s plaque gradually regressed. Itraconazole was administered for a total of 9 weeks (Fig. 1f). No recurrence has been observed for 5 years. M. irregularis was originally known as Rhizomucor variabilis, but it was renamed M. irregularis based on its DNA sequence. Cases of mucormycosis due to M. irregularis are rare, and only 14 cases have been reported in the English-language literature.3–5 However, it is worth noting that mucormycosis due to M. irregularis presents with unique clinical features. In contrast to classical mucormycosis, most M. irregularis infections affect
(a)
(d)
(b)
(e)
(c)
(f)
Figure 1. (a) An erythematous plaque displaying slight desquamation was present on the patient’s lower right leg. (b) A suppurative granuloma containing neutrophils, lymphocytes, and multinucleated giant cells was observed in the dermis. Scale bar, 250 lm. (c) Broad, ribbon-like, hyaline, aseptate hyphae were also detected (arrow, periodic acid-Schiff staining). Scale bar, 250 lm. (d) A wool-like, light yellow colony grown on Sabouraud dextrose agar. (e) A slide culture showing sporangiophores, which had formed a terminal, globose sporangium, packed with sporangiospores (lactophenol cotton blue stain). (f) Nine weeks after itraconazole treatment. immunocompetent patients and do not exhibit angioinvasion, especially in the early stages. Moreover, the majority of M. irregularis infections manifest as the superficial cutaneous type, progress chronically, and persist for several years on exposed sites. It is unknown why M. irregularis infections display these unique features. However, the lower thermotolerance of M. irregularis could be responsible for its lack of angioinvasion.4 Amphotericin B is the first-line treatment for M. irregularis infections (as well as for other types of mucormycosis), and
Correspondence: Kazutoshi Murao, M.D., Ph.D., Department of Dermatology, Institute of Health Biosciences, The University of Tokushima Graduate School, Kuramoto-cho, Tokushima City, Tokushima 770-8503, Japan. Email: [email protected]
© 2015 Japanese Dermatological Association
267
Letter to the Editor
itraconazole treatment has also been effective in other cases in addition to ours.5 M. irregularis infections usually display a good response to treatment, but we should remember that the associated lesions can become aggressive if left untreated.3
CONFLICT OF INTEREST:
None declared.
Yoshihiro MATSUDATE,1,2 Kazutoshi MURAO,1 Yoshio URANO,2 Kyoko YARITA,3 Katsuhiko KAMEI,3 Hiromi TAKEICHI,1 Yoshiaki KUBO1 1
Department of Dermatology, Institute of Health Biosciences, The University of Tokushima Graduate School, 2Division of Dermatology, Tokushima Red Cross Hospital, Tokushima, and 3Medical Mycology Research Center, Chiba University, Chiba, Japan
268
REFERENCES 1 Spellberg B, Edwards J Jr, Ibrahim A. Novel perspectives on mucormycosis: pathophysiology, presentation, and management. Clin Microbiol Rev 2005; 18: 556–569. 2 Ryan ME, Ochs D, Ochs J. Primary cutaneous mucormycosis: superficial and gangrenous infections. Pediatr Infect Dis 1982; 1: 110–114. 3 Lu XL, Shen Y, She X et al. Primary cutaneous zygomycosis caused by Rhizomucor variabilis: a new endemic zygomycosis? A case report and review of 6 cases reported from China. Clin Infect Dis 2009; 49: e39–e43. 4 Lu XL, Najafzadeh MJ, Dolatabadi S et al. Taxonomy and epidemiology of Mucor irregularis, agent of chronic cutaneous mucormycosis. Persoonia 2013; 30: 48–56. 5 Zhao Y, Zhang Q, Li L, Zhu J, Kang K, Chen L. Primary cutaneous mucormycosis caused by Rhizomucor variabilis in an immunocompetent patient. Mycopathologia 2009; 168: 243–247.
© 2015 Japanese Dermatological Association
doi: 10.1111/1346-8138.12788
LETTER TO THE EDITOR
Primary cutaneous mucormycosis caused by Mucor irregularis in an immunocompetent patient Dear Editor, Mucormycosis, which mainly affects immunocompromised patients, is a rare, life-threatening infection caused by the order Mucorales. Among the six clinical types of mucormycosis,1 cutaneous mucormycosis is the rarest and is further categorized into two types: (i) the gangrenous type, which only occurs in immunocompromised patients and progresses rapidly, and (ii) the superficial type, which develops in immunocompetent individuals, manifests as erythematous plaques, and progresses slowly.2 We present a case of superficial cutaneous mucormycosis caused by Mucor irregularis (M. irregularis) involving an immunocompetent patient. A 16-year-oldJapanese boy who was otherwise healthy presented with a 1-year history of a gradually enlarging plaque on his leg. A physical examination demonstrated an erythematous plaque exhibiting slight desquamation on his lower right leg, which he had scraped in a bicycle accident 2 years before (Fig. 1a). A histopathological examination detected a suppurative granuloma containing neutrophils, lymphocytes, and multinucleated giant cells in the dermis (Fig. 1b). Broad, ribbon-like, hyaline, aseptate hyphae were also observed (Fig. 1c). However, fungal hyphae and microvascular thrombosis were not detected in his blood vessels. Skin tissue specimens and skin scales cultured on Sabouraud dextrose agar at 25°C yielded wool-like, light yellow colonies, but no colony growth occurred at 38°C (Fig. 1d). Microscopic examinations of slide cultures detected sporangiophores, which had formed a terminal, globose sporangium. No apophyses were observed (Fig. 1e). These findings were consistent with Mucor fungi, and the isolate was identified as Mucor irregularis based on sequencing of the D1/D2 domain of the large subunit rRNA gene (GenBank accession no. IFM 57177). Before obtaining a diagnosis, we tried itraconazole (100 mg/ day), fluconazole (200 mg/day), and voriconazole (300 mg/day), independently, as empirical therapies, but none of them was effective. However, when we administered high-dose itraconazole (400 mg/day), the patient’s plaque gradually regressed. Itraconazole was administered for a total of 9 weeks (Fig. 1f). No recurrence has been observed for 5 years. M. irregularis was originally known as Rhizomucor variabilis, but it was renamed M. irregularis based on its DNA sequence. Cases of mucormycosis due to M. irregularis are rare, and only 14 cases have been reported in the English-language literature.3–5 However, it is worth noting that mucormycosis due to M. irregularis presents with unique clinical features. In contrast to classical mucormycosis, most M. irregularis infections affect
(a)
(d)
(b)
(e)
(c)
(f)
Figure 1. (a) An erythematous plaque displaying slight desquamation was present on the patient’s lower right leg. (b) A suppurative granuloma containing neutrophils, lymphocytes, and multinucleated giant cells was observed in the dermis. Scale bar, 250 lm. (c) Broad, ribbon-like, hyaline, aseptate hyphae were also detected (arrow, periodic acid-Schiff staining). Scale bar, 250 lm. (d) A wool-like, light yellow colony grown on Sabouraud dextrose agar. (e) A slide culture showing sporangiophores, which had formed a terminal, globose sporangium, packed with sporangiospores (lactophenol cotton blue stain). (f) Nine weeks after itraconazole treatment. immunocompetent patients and do not exhibit angioinvasion, especially in the early stages. Moreover, the majority of M. irregularis infections manifest as the superficial cutaneous type, progress chronically, and persist for several years on exposed sites. It is unknown why M. irregularis infections display these unique features. However, the lower thermotolerance of M. irregularis could be responsible for its lack of angioinvasion.4 Amphotericin B is the first-line treatment for M. irregularis infections (as well as for other types of mucormycosis), and
Correspondence: Kazutoshi Murao, M.D., Ph.D., Department of Dermatology, Institute of Health Biosciences, The University of Tokushima Graduate School, Kuramoto-cho, Tokushima City, Tokushima 770-8503, Japan. Email: [email protected]
© 2015 Japanese Dermatological Association
267
Letter to the Editor
itraconazole treatment has also been effective in other cases in addition to ours.5 M. irregularis infections usually display a good response to treatment, but we should remember that the associated lesions can become aggressive if left untreated.3
CONFLICT OF INTEREST:
None declared.
Yoshihiro MATSUDATE,1,2 Kazutoshi MURAO,1 Yoshio URANO,2 Kyoko YARITA,3 Katsuhiko KAMEI,3 Hiromi TAKEICHI,1 Yoshiaki KUBO1 1
Department of Dermatology, Institute of Health Biosciences, The University of Tokushima Graduate School, 2Division of Dermatology, Tokushima Red Cross Hospital, Tokushima, and 3Medical Mycology Research Center, Chiba University, Chiba, Japan
268
REFERENCES 1 Spellberg B, Edwards J Jr, Ibrahim A. Novel perspectives on mucormycosis: pathophysiology, presentation, and management. Clin Microbiol Rev 2005; 18: 556–569. 2 Ryan ME, Ochs D, Ochs J. Primary cutaneous mucormycosis: superficial and gangrenous infections. Pediatr Infect Dis 1982; 1: 110–114. 3 Lu XL, Shen Y, She X et al. Primary cutaneous zygomycosis caused by Rhizomucor variabilis: a new endemic zygomycosis? A case report and review of 6 cases reported from China. Clin Infect Dis 2009; 49: e39–e43. 4 Lu XL, Najafzadeh MJ, Dolatabadi S et al. Taxonomy and epidemiology of Mucor irregularis, agent of chronic cutaneous mucormycosis. Persoonia 2013; 30: 48–56. 5 Zhao Y, Zhang Q, Li L, Zhu J, Kang K, Chen L. Primary cutaneous mucormycosis caused by Rhizomucor variabilis in an immunocompetent patient. Mycopathologia 2009; 168: 243–247.
© 2015 Japanese Dermatological Association
