DERMATOMYCOSIS OF THE TOE WEB CAUSED BY Curvularia lunata

Dermatomycosis; Toe web; Curvularia lunata

BRIEF COMMUNICATION

DERMATOMYCOSIS OF THE TOE WEB CAUSED BY Curvularia lunata

Jorge O . LOPES(¹) & Neicy M. JOBIM(²)

KEYWORDS: Dermatomycosis; Toe web; Curvularia lunata.

Fungal infections of the feet are primarily caused by dermatophytes, but some nondermatophyte fungi have been implicated in several patients, particularly for toe nail infections. These infections clinically mimic dermatophytosis, and when examined microscopically with potassium hydroxide, the agents resemble the dermatophytes. However, correct identification is very important since some nondermatophyte fungi are refractory to conventional therapy.

We communicate a case of dermatomycosis of the toe web caused by Curvularia lunata, mimicking intertriginous tinea pedis.

The patient was a 50-year-old married white woman, commercial employee, with a scaling lesion in the web between the fourth and fifth toes of the right foot of six month duration. Skin scrapings examined in 10% potassium hydroxide solution revealed hyaline branched septate hyphae, and irregular round cells, without arthroconidia (Fig. 1). Cultures on cycloheximide free Sabouraud´s medium incubated at 25º C revealed the growth of effuse, dark-gray colonies. Microscopically branched septate, hyaline to brown hyphae, and curved or nearly straight conidia with three septa, the subterminal cell curved, swollen and distinctly larger than the remaining, characteristic of C. lunata were seen (Fig. 2). Direct examination were positive in more five samples collected during a 45 days period, and C. lunata grew in all occasions. The patient was treated with a cream containing isoconazole nitrate during three months, with healing of the lesion.

Fig. 1
- Skin scrapings: hyaline branched septate hyphae, and irregular round cells (10% potassium hydroxide), x250.

Fig. 2
- C. lunata: hyaline to brown hyphae and conidia (Lactophenol), x250.

Fungi of the Curvularia genus are ubiquitous organisms, occurring more frequently in soil and decaying plants. Although rarely pathogenic, Curvularia species have been implicated in cases of visceral infections, such as endocarditis⁸, peritonitis¹¹, hepatosplenic abscess¹⁴, urinary¹³, pulmonary¹⁰, cerebral⁴, and disseminated infections³. Keratitis¹⁵, allergic or invasive sinusitis², and allergic bronchoalveolar disease⁷ have also been reported. Rarely subcutaneous infections are noted, such as phaeohyphomycosis⁶, leg ulcer⁵, and mycetoma¹². Superficial infections are extremely rare, and only a case of onychomycosis was reported¹.

Dermatomycosis is a term used to encompass several clinically distinctive infections of the skin caused by nondermatophyte fungi, including dematiaceous and hyaline hyphomycetes. It is important to emphasize that Curvularia species produce dark colonies on the agar media, but in tissues the fungal elements are hyaline to brown, with varying morphologic features⁹. Hence, only a correct diagnosis by means of microscopic examination and cultures on media that do not contain cycloheximide, will allow proper identification of the causative agent.

REFERENCES

1. BARDE, A.K. & SINGH, S.M. - A case of onychomycosis caused by Curvularia lunata (Wakker) Boedijn. Mykosen, 26: 311-316, l983.

2. BERRY, A.J.; KERKERING, T.M.; GIORDANO, A.M. & CHIANCONE, J. - Phaeohyphomycotic sinusitis. Pediat. infect. Dis., 3: 150-152, l984.

3. DE LA MONTE, S.M. & HUTCHINS, G. M. - Disseminated Curvularia infection. Arch. Path. Lab. Med., 109: 872-874, l985.

4. FRIEDMAN, A.D.; CAMPOS, J.M.; RORKE, L.B.; BRUCE, D.A . & ARBETER, A.M. - Fatal recurrent Curvularia brain abscess. J. Pediat., 99: 413-415, 1981.

5. GARCIA, J.; BERG, D.; MURRAY, J.; SCHELL, W. & PERFECT, J. - Chronic leg ulcer due to Curvularia pallescens. J. cutan. Path., l9: 523, l992.

6. GRIESHOP, T.J.; YARBROUGH, D. & FARRAR, W.E. - Case report: phaeohyphomycosis due to Curvularia lunata involving skin and subcutaneous tissue after an explosion at a chemical plant. Amer. J. med. Sci., 305: 387-389, l993.

7. HALWIG, J.M.; BRUESKE, D.A.; GREENBERGER, P.A.; DREISIN, R.B. & SOMMERS, H.M. - Allergic bronchopulmonary curvulariosis. Amer. Rev. resp. Dis., 132: 186-188, 1985.

8. KAUFMAN, S. M. - Curvularia endocarditis following cardiac surgery. Amer. J. clin. Path., 56: 466-470, l97l.

9. KWON-CHUNG, K.J. & BENNETT, J.E. - Phaeohyphomycosis (chromomycosis, phaeosporotrichosis, cerebral chromomycosis). In: KWON-CHUNG, K.J. & BENNETT, J.E. Medical mycology. Philadelphia, Lea & Febiger, l992. p. 620-677.

10. LAMPERT, R.P.; HUTTO, J.H.; DONNELLY, W.H. & SHULMAN, S.T. - Pulmonary and cerebral mycetoma caused by Curvularia pallescens. J. Pediat., 91: 603-605, l977.

11. LOPES, J.O.; ALVES, S.H.; BENEVENGA, J.P. et al. - Curvularia lunata peritonitis complicating peritoneal dialysis. Mycopathologia (Den Haag), 127: 65-67, 1994.

12. MAHGOUB, E.S. - Mycetomas caused by Curvularia lunata, Madurella grisea, Aspergillus nidulans and Nocardia brasiliensis in Sudan. Sabouraudia, ll: l79-l82, 1973.

13. ROBSON, A.M . & CRAVER, R.D. - Curvularia urinary tract infection: a case report. Pediat. Nephrol., 8: 83-84, l994.

14. SHIGEMORI, M.; KAWAKAMI, K.; KITAHARA, T. et al. - Hepatosplenic abscess caused by Curvularia boedijn in a patient with acute monocytic leukemia. Pediat. infect. Dis. J., l5: 1128-1129, l996.

15. WIND, C. A . & POLACK, F. M.- Keratomycosis due to Curvularia lunata. Arch. Ophthal., 84: 694-696, 1970.

Correspondence to: Jorge O . Lopes, Departamento de Microbiologia e Parasitologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brasil. Fone: [phone]. Fax [phone]. E-mail: [e-mail]

Received: 4 February 1998.

Accepted: 8 April 1998.

(1

)Laboratório de Pesquisas Micológicas, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil.

(2

)Médica Dermatologista.

Publication Dates

• Publication in this collection
  02 Mar 1999
• Date of issue
  Sept 1998

History

• Received
  04 Feb 1998
• Accepted
  08 Apr 1998