Mycological exarnination in pachyonychia 
Short report 
MYCOLOGICAL EXAMINATION 
IN PACHYONYCHIA CONGENITA 
A. Kansky, M. Dolenc-Voljč, P.E. Bowden and M. Belič 
ABSTRACT 
Introduction. Pachyonychia congenita (PC) is a hereditary disorder of keratinization characterized by extremely 
thickened nails, follicular hyperkeratosis, insular palmoplantar keratoderma and thickened, whitish lingual and 
buccal mucosa sometimes involving also gingivae. It was established during the last few years that this disorder 
is due to mutations of keratin genes. The additional role of yeasts in the pathogenesis of PC was sometimes 
questioned, however no systemic study could be traced in the literature. 
Methods. Mycologic investigations of nails and insular keratoses were carried out in eight Slovenian patients 
with PC-1: direct microscopy and cultivation on Sabouraud's dextrose agar. In ali these patients the keratin 
mutations had been defined. 
Results. Candida species (Cand sp) were isolated from fingernails in two and Aspergillus sp in another patient. 
From toenails Cand sp was isolated in 2 and Rodotontla sp in another patient. From the keratinous material 
from the soles Trichophyton mentagrophytes was isolated in two patients and Cand sp in another. 
Conclusion. Detection of Cand sp, Aspergillus sp or Rodotontla sp, spores in just a few patients is considered 
to be an accompanying phenomenon. 
KEY WORDS 
mycological examination, nails, pachyonychia congenita, PC-1, yeasts 
INTRODUCTION 
Pachyonychia congenita (PC) is a well-defined 
entity within the broad group of hereditary palmo-
plantar keratodermas (HPPK). According to McKusick 
(1) two broad phenotypic variants of PC are recog-
acta dennatovenerologica A.P.A. Vol 7, 98, No 3-4 
nized: type Jadassohn-Lewandowsky or PC-1 (MIM 
167200) and type Jackson-Lawler or PC-2 (MIM 
167210). PC-1 is characterized by a thickened, brownish 
nail plate with a rough surface, insular hyperkeratoses 
of palms and soles, follicular hyperkeratosis affecting 
135 
Mycological examination in pachyonychia 
Table l. Mycological investigations of fingemails in 8 patients with pachyonychia congenita - type l. 
3 (yeasts) direct microscopy 
culture 
5 
4 4: Candida sp, Rhodotorula sp. 1 
1 
2 
L 
Aspergi/lus sp 
Candida sp 
specially the temples, nose and extensor surfaces of 
the arms, as well as by thickened, whitish mucosa 
of the tongue and cheeks (leukokeratosis) (2,3). In 
PC-2 additionally to thickened nails, sebaceous cysts 
and sometimes teeth at birth (neonatal teeth) are 
expressed, while the other above listed symptoms 
may be less prominent or absent. The thickened 
nails are in the majority of patients present at birth, 
but they may appear within the first 6 months. 
The genetic deficiencies in PC have been extensively 
studied by a few groups of authors. In PC-2 the 
disorder was linked to mutations in keratin Kl 7 and 
in PC-1 to K16 (4). In the eight Slovenian patients 
who have been investigated, K6a was affected by 
mutations (5). In five of these patients identical 
mutations in the central Rod Domain (helix) of 
K6a were identified: removal of one of the two 
adjacent asparagines Nl 70/171 (families A and O); 
in two patients (family P) a F174S mutation, phenyl-
alanin to serin, and in one patient (family L) a 
Nl 71K ( asparagine to lysine) mutations were detected 
(5). 
PC is generally a rare disorder, however in the 
Slovenian and Craatian populations its appearance 
is not unusual (6,7). The fact that the symptoms are 
expressed already in babies bas led to the misinterpre-
tation of this condition as candidiosis, so that certain 
patients have been unnecessarily exposed to systemic 
antimycotic treatment. 
As such erraneous view stili exists we decided to 
investigate our PC-1 patients mycologically. 
Table 2. Mycological investigations of toenails in 8 
patients with pachyonychia congenita - type l. 
direct 
microscopy 
culture 
136 
5 
5 
3 (yeasts) 
3: Rhodotoru/a sp 
Candida sp 
1 L 
2 P 1/1, P 11/2 
A 11/2 
P 1/1, P 11/2 
MATERIALS AND METHODS 
The investigation focused on eight patients with 
clear-cut symptoms of PC-1, in whom the mutations 
of the keratin gene (KRT6a) were praved at the 
molecular leve!. All these Slovenian patients with 
PC-1 were available for mycological investigations. 
Their ages ranged at the tirne of this investigation 
from 9 years (SP) to 69 years (LD). Scrapings were 
taken by the usual procedure from finger- and 
toenails, as well as from hyperkeratotic lesions of 
the soles and palms. Direct micrascopic investigation 
was done after the digestion of the hyperkeratotic 
material with 10% KOH. The culture was performed 
on Petri dishes on Sabouraud's dextrase agar (Difco). 
RESULTS 
Only a few spores and no hyphae were detected, 
except in patient LD, in whom a larger number of 
spores was found on toenails. Cand sp were isolated 
from the fingernails of two patients, Cand sp together 
with Rhodotorula sp in one and Aspergillus sp in 
one. Fram the toenails Cand sp were isolated in 
two and Rodotorula sp in one patient. Details are 
given in Tables 1 and 2. 
Fram the keratinous material on soles Trichophyton 
mentagrophytes was isolated in two patients and 
Cand sp m one patient. Scrapings from palms were 
negative m 4 patients. Table 3. 
DISCUSSION 
No systematic mycologic investigation of the affected 
nails in PC patients could be detected in the 
literature and only a few sporadic observations were 
found. Forslind et al (8) mentioned that colonies of 
Candida albicans were detected in leukokeratotic 
lesions of oral mucosa in one, while the other 
patient under their observation was suffering from 
acta dennatovenerologica A.P.A. Vol 7, 98, No 3-4 
Mycological examination in pachyonychia 
Table 3. Mycological investigations of the keratinous 
material from the soles in 7 patients with pachyonychia 
congenita - type l. 
direct 
microscopy 
culture 
6 
4 
1 (mycelium) 
3: Tr. mentagrophytes 2 
Candida sp 1 
A 1/1 , P 1/1 
P 11/2 
paronychia probably caused by Candida albicans. 
Mawhinney et al (9) as well as Sivasundram et al 
(10) mentioned chronic candidosis in the mouth, 
only Paller et al (11) mentioned concomitant candidal 
organisms of the nails in one out of their five 
patients. In certain publications mycologic investigations 
of the nails are not mentioned at ali (12). 
A limited number of skin disorders may cause 
differential diagnostic difficulties. It is known that 
skin and mucosal symptoms in mucocutaneous 
candidosis, in immunologically handicapped children, 
can be to some extent similar to PC. However in 
such cases mycology is helpful by finding hyphae 
and numerous spores, thus indicating a pathogenic 
role of yeasts, mostly Cand sp. 
Another diagnostic pitfall is the rare dominant 
form of epidermolysis bullosa dystrophica (EBD), as 
it was correctly mentioned by Moldenauer and Ernst 
in 1968 (13). Such diagnostic problem may arise 
when there are present only a few thickened nails 
and a history of blistering and extensive scars. Some 
cases described in the literature as PC, are most 
probably cases of the dominant EBD (6,14). Other 
rare confusing disorders, which have also to be 
taken into consideration, are various hereditary and 
nonhereditary dystrophies of the nails. 
Molecular DNA investigation, which enables the 
detection of keratine gene mutations KRT6a, KRT16, 
KRTl 7 or KRT6b, permits nowadays a definite 
genetic confirmation of PC. 
Finding dermatophytes on the soles of PC patients 
is not surprising as hyperhydrosis is a frequent 
accompanying symptom in HPPKs. Detection of 
dermatophytes in patients with the diffuse HPPK 
of the Unna-Thost type was reported by Gamborg-
Nielsen in 33 out of 91 (36.2%) Swedish patients 
(15). 
CONCLUSIONS 
It has been praven unequivocally that PC is a 
hereditary disorder of keratinization. A number of 
mutations have been identified. Detection of a few 
spores of Candida sp, Aspergillus sp or Rhodotorula 
sp in some of our patients should be considered 
only an accompanying and not an etiological pheno-
menon. 
REFERENCES 
l. McKusik VA. Mendelian Inheritance in Man, 11th 
Edition, J Hopkins University Press, Baltimore, 1994, 
1086. 
2. Kansky A, Penko M, Milakic-Snoj M. Pachyonychia 
congenita. Acta Derrnatoven APA, 1994;3: 153-60. 
3. Dah! PR, Mazen S, Daoud D, Su WP. Jadassohn-
L ewandowsky syndrome (Pachyonychia congenita). 
Seminars Derrnatol 1995;14(2): 129-34. 
4. McLean WH et al. Keratin 16 and keratin 17 
mutations cause pachyonychia congenita. Natur Genet 
1995; 9: 273-8. 
5. Bowden PE, Haley JL, Kansky A et al. Mutation of 
a type II keratin gene K 6a in pachyonychia congenita. 
Natur Genet 1995; 10: 363-5. 
acta dennatovenerologica A .P.A. Vol 7, 98, No 3-4 
6. Franzot ], Kansky A, Kavčič Š. Pachyonychia congenita 
(Jadassohn-Lewandowsky syndrome). A review of 14 
cases in Slovenia. Demiatologica 1981; 162: 462-72. 
7. Kansky A, Basta Juzbašic A, Videnic N et al. 
Pachyonychia congenita Jadassohn-Lewandowsky synd-
rome. Evaluation of symptoms in 36 patients. Arch 
Dermatol Res 1993; 285: 36-7. 
8. Forslind B, Nyelen B, Swanbeck G et al. Pachyonychia 
Congenita, A Histologic and Microradiographic Study. 
Acta Derrnat Venero! (Stockh) 1973; 53: 211-6. 
9. Mawhinney H, Creswell S, Beare M. Pachyonychia 
congenita with candidiasis. Ciin Exper Derrnatol ·1981; 
6: 145-9. 
10. Sivasundram A, Rajagopalan K, Sarojini T. Pachy-
137 
Mycological examination in pachyonychia 
onychia Congenita lnt Dennatol 1985; 24: 179-80. 
11. Paller AS, Moore JA, Scher R. Pachyonychia 
Congenita Tarda A late-Onset Fonn of Pachyonychia 
Congenita Arch Dennatol 1991; 127: 701-3. 
13. Moldenauer E, Ernst K Das Jadasohn-Lewandowsky 
Syndrome. Hautant 1968; 10: 441-7. 
14. Haber RM, Rose TH. Autosomal recessive 
pachyonychia congenita. Arch Dermatol 1986; 122: 
919-23. 12. Su WPD, Soo /C, Hammond DE, Gordan H. 
Pchyonychia congenita: a clinical study of 12 cases 
and review of literature. Pediatr Dennatol 1990;7: 33-8. 
15. Gamborg-Nielsen P. Hereditary Palmoplantar 
Keratodenna in the Northernmost County of Sweden. 
Acta Denn Venereol (Stockh) 1985; 65: 224-9. 
138 
AUTHORS' ADDRESSES 
Aleksej Kansky MD, PhD, Department of Dermatology, Clinical Center, Zaloška 2, 
1525 Ljubljana, Slovenia 
Mateja Dolenc-Voljč MD, dermatologist, same address 
Paul E. Bowden PhD, Department of Dermatology, University of Walws College of, Heath Park, 
Cardiff CF4 4XN, United Kingdom 
Mirjam Belič MD, dermatologist, Department of Dermatology, Teaching Hospital, 2000 Maribor, 
Slovenia 
acta dermatovenerologica A.P.A. Vol 7, 98, No 3-4