Nail fungal infections and treatmentRobert Baran, MD*

Nail Disease Centre, 42 rue des Serbes, 06400, Cannes, France

Four main portals for fungi can be identified on

the nail, each resulting in different clinical patterns

of infection [1] (Fig. 1):

1. Via the distal subungual area and the lateral

nail groove, leading to distal lateral subun-

gual onychomycosis. The fungus invades the

horny layer of the hyponychium or the nail

bed, then the undersurface of the nail plate,

which becomes opaque. Endonyx onychomy-

cosis is a variant of this type.

2. Via the dorsal surface of the nail plate, pro-

ducing superficial onychomycosis. Superficial

white onychomycosis is normally confined to

the toenails. Superficial black onychomycosis,

its counterpart, is very rare.

3. Via the undersurface of the proximal nail

fold, which appears normal in proximal sub-

ungual onychomycosis. In patients with

AIDS the term ‘‘polydactylous acute proxi-

mal nail dystrophy’’ might be appropriate

for this type of infection. Proximal leukony-

chia associated with paronychia is produced

by nondermatophyte-moulds.

4. Secondary total dystrophic onychomycosis

represents the most advanced form of all the

types described above (Fig. 2). In contrast to

this form, primary total dystrophic onycho-

mycosis is observed only in patients suffering

from chronic mucocutaneous candidiasis or

in other immunodeficiency states.

The diagnosis of onychomycosis always

requires laboratory confirmation. Mycological

diagnosis is based on detection of fungal elements

in direct microscopy preparations and identifica-

tion of the responsible fungus by culture. In

repeated false negative mycological results, histo-

pathological examination of nail keratin may be

helpful.

Treating onychomycosis may be a tantalizing

problem depending on the age of the patient, the

condition’s modifications, and the status of the

peripheral circulation. The clinician will have to

choose among three main possibilities: topical

therapy with the new nail lacquers, new oral drugs,

and removal of the nail plate. A combination of

different modalities often provides the best option.

The first line of therapy for mild or moderate

fungal invasion that spares the proximal third of

the nail plate is topical monotherapy with the anti-

fungal nail lacquers that act as a transungual drug

delivery system.

Six months of ineffective monotherapy provide

an indication for further treatments. When the

proximal third of the nail is involved, however,

double pronged therapy should be considered as a

first step and ciclopirox (Penlac� or amorolfine,

which is not yet available in the United States)

should be combinedwith systemicmedication. This

will also produce effective oral therapy against

tinea pedis, which often precedes onychomycosis.

Usually, terbinafine, the first systemic fungi-

cidal drug against dermatophytes, is prescribed

(250 mg/daily for six weeks for fingernail infection,

and for threemonths for toenail infection). Itracon-

azole has the broadest in vitro spectrum of the

oral antifungals. The recommended schedule is

200 mg twice a day, daily for one week each month

(two months for fingernail infections and three to

four months for toenails). Fluconazole may be a

useful intermittent regimen in patients taking mul-

tiple medications; 150 to 300 mg are administered

once a week for 6 to 9 months.

Unfortunately, even in the most successful ther-

apeutic trials at least 25% of patients do not* E-mail address: baran.r@club-internet.fr (R. Baran).

0749-0712/02/$ - see front matter � 2002, Elsevier Science (USA). All rights reserved.

PII: S 0 7 4 9 - 0 7 1 2 ( 0 2 ) 0 0 0 3 7 - 9

Hand Clin 18 (2002) 625–628

respond to systemic treatment. The reasons for

failure may be complex, but may include poor

drug penetration due to the presence of extensive

onycholysis, lateral nail disease, or dermatophy-

toma (onycholytic pockets or canals on the under-

surface of the nail, filled with necrotic debris of

keratin and large compact amount of fungi). Such

areas may only be amenable to physical interven-

tion and removal of the diseased material. There

is, therefore, a renewed interest in surgical,

mechanical, or chemical interventions in the treat-

ment of dermatophyte onychomycosis.

The place of nail surgery in the treatment

of onychomycosis

The removal of as much diseased nail as possi-

ble is helpful, but only as an adjunct to oral or top-

ical antifungal agent, despite anecdotal reports. In

addition to dermatophyte nail infections, surgical

removal is also particularly helpful in the treat-

ment of onychomycosis caused by moulds [2–5].

Total surgical removal of the nail has some-

times been discouraged, however, because the dis-

tal nail bed may shrink and become dislocated

dorsally. Also, the loss of counter pressure pro-

duced by the removal of the nail plate allows

expansion of the distal soft tissue and the distal

edge of the regrowing nail then embeds itself [6].

This complication can be prevented, however, by

the use of a prosthetic nail (false plastic fingernail

sold at drugstores) so that the width of the nail bed

is maintained and ingrowth is avoided [7].

Total nail avulsion

The removal of the nail plate can be carried out

using distal or proximal approaches. In both tech-

niques, insertion of a blunt instrument back and

forth between the horny layer of the proximal nail

fold and the nail plate loosens the proximal nail

fold attachment.

Distal approach

In the more commonly used distal approach, a

Freer septum elevator or a dental spatula is in-

serted between the nail plate and nail bed. The nail

is separated from its nail bed attachment using

proximal force applied using anterior-posterior

movements so as not to injure the longitudinal

ridges of the nail bed. The detachment is completed

by firmly pushing the instrument into the postero-

lateral corners of the nail plate. Then, one of the

lateral edges is grasped with a sturdy hemostat,

and extracted with an upwards and circular move-

ment to accomplish the removal of the nail plate.

Proximal approach

The proximal approach for nail avulsion is

advised when the subungual distal area adheres

strongly to the nail plate and the hyponychium

can be injured by the introduction of the spatula.

The proximal nail fold is freed as described above.

The spatula is then used to reflect the proximal nail

fold, and is delicately inserted under the base of the

nail plate where adherence is weak. The instrument

is advanced distally following the natural cleavage

plane, and this operation is repeated on the entire

width of the subungual region. After freeing the

last attachments, the nail plate is easily pulled out.

Partial nail avulsion

Partial distal avulsion requires only separation

of the nail from subungual tissue. This procedure

can be performed under local anesthesia in selected

patients where the fungal infection is of a limited

Fig. 2. Development of total dystrophic onychomycosis.Fig. 1. Typology of onychomycosis.

626 R. Baran / Hand Clin 18 (2002) 625–628

extent. An affected portion of the nail plate may

be removed in one session, even when the disease

has reached the deeper regions of the subungual

tissue beneath the proximal nail fold (Fig. 3A,B).

Commonly, an English anvil nail splitter or a

double action bone rongeur are used for this

procedure.

Partial surgical section of the lateral or med-

ial segment of the nail plate may be sufficient

for the treatment of distal lateral subungual

Fig. 3. (A) Lateral and proximal onychomycosis. (B) Partial surgical avulsion.

Fig. 4. (A) Recalcitrant chronic Candida paronychia of the thumb with nail plate invasion. (B) Surgical excision of a

crescent of thickened nail fold, followed by nail avulsion.

627R. Baran / Hand Clin 18 (2002) 625–628

onychomycosis. Therefore, enough normal nail is

left on the toe to counteract the upward forces

exerted on the distal soft tissue when walking, and

this will prevent the appearance of a distal nail wall.

In proximal subungual onychomycosis, re-

moval of the nonadherent base of the nail plate,

cut transversely, leaves the distal portion of the

nail in place, which decreases discomfort.

Where Candida or, more rarely, dermatophytes

result in onycholysis, the detached portion of the

nail plate should be thoroughly clipped away. This

facilitates the daily application of a topical anti-

fungal drug until nail regrowth is complete. In

paronychia with Candida lateral nail-edge involve-

ment or mixed infection, the affected nail keratin

should be surgically removed. Recalcitrant Can-

dida paronychia with secondary nail-plate inva-

sion may be treated by surgical excision of a

crescent of thickened nail fold followed by nail

avulsion (Fig. 4A,B).

In any type of surgically treated onychomyco-

sis, the avulsed nail segment must always include

a margin of normal nail and the nail bed should

be treated with the conventional antifungal oint-

ments.

It has been shown that partial surgical avulsion

of the nail as a treatment of onychomycosis, in

combination with griseofulvin or ketoconazole

therapy, reduced the duration of the oral antifun-

gal treatment by 50% [7]. Recently, good results

have been obtained by combining surgical tech-

niques with either intermittent [8] or short dura-

tion use of new oral antifungal drugs [9]. This

combination may be of particular use in limited

dermatophyte toenail infection or in cases of

treatment failure following conventional oral

treatment. The addition of the antifungal nail

lacquers on the remaining nail keratin allows a

‘‘triple therapy’’ model offering the best results.

Since the introduction of the newer oral antifungal

agents, there is no longer room for matricectomy

in the treatment of severe onychomycosis, despite

some isolated reports [10].

The place of chemical avulsion

In patients at risk (immunosuppressive condi-

tions, immunosuppressive therapy, peripheral vas-

cular disease), chemical avulsion is a painless

method that has superseded partial surgical avul-

sion [11]. It may be repeated as often as necessary.

Urea ointment appears to focus its action on the

bond between the nail keratin and the diseased nail

bed; it spares the normal nail tissue.

Forty percent urea ointment is applied to the

nail plate after protecting the surrounding skin,

with adhesive dressing for example. The entire dis-

tal digit is then wrapped for a week.

Blunt dissection, using a nail elevator and nail

clipper, leaves the remaining portion of normal

nail plate intact. Following removal of the dis-

eased part of the nail, topical antifungal agents

should be applied for several months under occlu-

sion, especially if there is no associated systemic

therapy.

Despite its efficacy, such a treatment is difficult

to apply in the elderly, tedious when several digits

are affected, or ineffective when the proximal por-

tion of the nail plate is invaded by fungal organ-

isms beneath the nail fold.

References

[1] Baran R, Hay RJ, Tosti A, Haneke E. In: A new

classification of onychomycosis. Br J Dermatol

1998;119:567–71.

[2] Baran R, Hay R, Haneke E, Tosti A. In: Onycho-

mycosis: the current approach to diagnosis and ther-

apy. London: Martin Dunitz Ltd.; 1999 Chapter 7.

[3] Mc Innes BD, Dockery GL. Surgical treatment of

mycotic toenails. J Am Podiatr Med Assoc 1997;

87:557–64.

[4] Baden HP. Treatment of distal onychomycosis with

avulsion and topical antifungal agents under

occlusion. Arch Dermatol 1994;130:558–9.

[5] Cohen PR, Scher RK. Topical and surgical treat-

ment of onycomycosis. J Am Acad Dermatol

1994;31:S47–77.

[6] Fowler AW. Excision of the germinal matrix: a

unified treatment for toenail and onychogryphosis.

Br J Surg 1958;45:382.

[7] Baran R, Hay R. Partial surgical avulsion of the

nail in onychomycosis. Clin Exp Dermatol 1985;10:

413–8.

[8] Dominguez-Cherit J, Teixera F, Arenas R. Com-

bined surgical and systemic treatment of onycho-

mycosis. Br J Dermatol 1999;140:778–80.

[9] Goodfield MJD, Evans EGV. Combined treatment

with surgery and short duration oral antifungal

therapy in patients with limited dermatophyte toe-

nail infection. J of Dermatol Treat 2000;11:259–62.

[10] Nahabedian MY. Multiple-digit onychomycosis: a

simple surgical cure. Ann Plast Surg 2000;45:

446–50.

[11] South DA, Farber E. Urea ointment in non surgical

avulsion of nail dystrophies. Reappraisal. Cutis

1980;26:609–12.

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