The therapeutic outcome of onychomycoses is uncertain. Comparative short-term efficacy studies on antifungals abound and report contradictory findings. Few unbiased follow-up studies have scrutinized the long-term outcome. Basically, none of the current antifungals can guarantee cure in all instances. In addition, relapses are not rare. The causes of therapeutic failure in onychomycoses are multiple. The most important are the lack of diagnostic accuracy, inadequate antifungal choice or delivery modality, and presence of dormant conidia, sequestrated mycelium pockets or resistant fungal species. The concept of fungicidal drug derived from selected in vitro studies appears irrelevant in clinical practice.

Keywords:
Antifungal, Onychomycosis, Conidia, Relapse, Corneofungimetry
1.
Arrese JE, Piérard-Franchimont C, Piérard GE: A plea to bridge the gap between antifungals and the management of onychomycosis. Am J Clin Dermatol 2001;2:281–284.
2.
Evans EGV, Sigurgeirsson B: Double blind, randomised study of continuous terbinafine compared with intermittent itraconazole in treatment of toenail onychomycosis. The LION study Group. BMJ 1999;318:1031–1035.
3.
Sigurgeirsson B, Olafsson JH, Steinsson JB, Paul C, Billstein S, Evans EG: Long-term effectiveness of treatment with terbinafine vs itraconazole in onychomycosis: A 5-year blinded prospective follow-up study. Arch Dermatol 2002;138:353–357.
4.
Arrese JE, Piérard-Franchimont C, Piérard GE: Facing up to the diagnostic uncertainty and management of onychomycoses. Int J Dermatol 1999;38(suppl 2):1–6.
5.
Piérard GE, Arrese JE, Pierre S, Bertrand C, Corcuff P, Lévêque JL, Piérard-Franchimont C: Diagnostic microscopique des onychomycoses. Ann Dermatol Venereol 1994;121:25–29.
6.
Scherer WP, McCreary JP, Hayes WW: The diagnosis of onychomycosis in a geriatric population: A study of 450 cases in South Florida. J Am Podiatr Med Assoc 2001;91:456–464.
7.
Elewski BE: Diagnostic techniques for confirming onychomycosis. J Am Acad Dermatol 1996;35:S6–S9.
8.
Haldane DJ, Robart E: A comparison of calcofluor white, potassium hydroxide, and culture for the laboratory diagnosis of superficial fungal infection. Diag Microbiol Infect Dis 1990;13:337–339.
9.
Piérard GE, Arrese JE, De Doncker P, Piérard-Franchimont C: Present and potential diagnostic techniques in onychomycosis. J Am Acad Dermatol 1996;4:273–277.
10.
Gianni C, Morelli V, Cerri A, Greco C, Rossini P, Guiducci A, Braidotti P, Calcaterra R, Papini M: Usefulness of histological examination for the diagnosis of onychomycosis. Dermatology 2001;202:283–288.
11.
Arrese JE, Piérard-Franchimont C, Greimers R, Piérard GE: Fungi in onychomycosis: A study by immunohistochemistry and dual flow cytometry. J Eur Acad Dermatol Venereol 1995;4:123–130.
12.
Summerbell RC: Epidemiology and ecology of onychomycosis. Dermatology 1997;194(suppl 1):32–36.
13.
Ginter G, Rieger E, Heigl K, Propst E: Increasing frequency of onychomycosis: Is there a change in the spectrum of infectious agents? Mycoses 1996;39(suppl 1):118–122.
14.
Greer DL: Evolving role of nondermatophytes in onychomycosis. Int J Dermatol 1995;34:521–524.
15.
Ellis DH, Marley JE, Watson AB, Williams TG: Significance of non-dermatophyte moulds and yeasts in onychomycosis. Dermatology 1997;194(suppl 1):40–42.
16.
Gupta AK, Cooper EA, MacDonald P, Summerbell RC: Utility of inoculum counting (Walshe and English criteria) in clinical diagnosis of onychomycosis caused by nondermatophytic filamentous fungi. J Clin Microbiol 2001;39:2115–2121.
17.
Shuster S: Onychomycosis: Making sense of the assessment of antifungal drugs. Acta Derm Venereol 1998;78:1–4.
18.
Shuster S, Baran R: Recurrence of fungal nail disease and the dissociation of relapse from re-infection. Acta Dermatovenerol 2001;81:154–155.
19.
Piérard GE: Onychomycosis and other superficial fungal infections of the foot in the elderly: A pan-European survey. Dermatology 2001;202:220–224.
20.
De Doncker P, Piérard GE: Acquired nail beading in patients receiving itraconazole: An indicator of faster nail growth? A study using optical profilometry. Clin Exp Dermatol 1994;19:404–406.
21.
Roberts DT, Evans EG: Subungual dermatophytoma complicating dermatophyte onychomycosis. Br J Dermatol 1998;138:189–190.
22.
Piérard GE, Piérard-Franchimont C, Arrese JE: The boosted oral antifungal treatment for onychomycosis beyond the regular itraconazole pulse dosing regimen. Dermatology 2000;200:185–187.
23.
Piérard GE, Piérard-Franchimont C, Arrese JE: The boosted antifungal topical treatment (BATT) for onychomycosis. Med Mycol 2000;38:391–392.
24.
Bradley MC, Leidich S, Isham N, Elewski BE, Ghannoum MA: Antifungal susceptibilities and genetic relatedness of serial Trichophytum rubrum isolates from patients with onychomycosis of the toenail. Mycoses 1999;2:105–110.
25.
Piérard GE, Arrese JE, De Doncker P: Antifungal activity of itraconazole and terbinafine in human stratum corneum: A comparative study. J Am Acad Dermatol 1995;32:429–435.
26.
Arrese JE, De Doncker P, Odds F, Piérard GE: Reduction in the growth of non-dermatophyte moulds by itraconazole: Evaluation by corneofungimetry bioassay. Mycoses 1998;41:461–465.
© 2003 S. Karger AG, Basel
2003
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.