Skin diseases associated with Malassezia species in humans. Clinical features and diagnostic criteria

Malassezia yeasts not only cause the well known pityriasis versicolor and folliculitis, but also play an important role in other skin diseases, including seborrheic dermatitis and atopic dermatitis. The presence of Malassezia yeasts may be confirmed by direct microscopic examination and cultures of skin scrapings. In pityriasis versicolor the direct microscopic examination is the rapidest and surest test for confirming the clinical diagnosis. The preparation will show a cluster of globose budding spores with thick or double wall and short hyphae. For detecting Malassezia in the other diseases the cultures is preferable. Culture is useful both for confirming the clinical diagnosis and for epidemiological investigations. The identification of the Malassezia species is not easy. The microscopic observation of the colony direct towards the identification of Malassezia species, but it is not enough to identify the colonies definitely. Several biochemical tests are necessary for a precise identification, such as catalase reaction, growth on media without lipid sources, ability to utilize hydrophilic emulsifiers as sole lipid source, esculin test, tryptophan test.

Hot tub folliculitis or hot hand–foot syndrome caused by Pseudomonas aeruginosa

Pseudomonas aeruginosa is a ubiquitous gram-negative rod that can cause a well-recognized, acquired skin infection from bacterial colonization of contaminated water called "hot tub folliculitis." We report an outbreak of pseudomonas skin infection associated with the use of a hot tub at a pool party in 33 children. In particular, 2 of the children were admitted to our hospital; both presented with high leukocyte counts, intermittent low grade fevers, and painful, erythematous nodules and papules on their palms and soles. One of the 2 children also presented with small erythematous pustular lesions on the face and trunk, which led to the diagnosis. Cultures from these pustules grew P aeruginosa. Thirty two other children at this pool/hot tub party developed similar lesions of varying severity 6 to 48 hours after the party. These findings were most consistent with the diagnosis of pseudomonas folliculitis/hot hand.

Pulsed-field gel electrophoresis patterns and antimicrobial susceptibility phenotypes for coagulase-positive staphylococcal isolates from pustules and carriage sites in dogs with superficial bacterial folliculitis

OBJECTIVE

To determine whether coagulase-positive staphylococcal isolates that are genotypically the same strain obtained from pustules and carriage sites of individual dogs with superficial bacterial folliculitis have the same antimicrobial susceptibility phenotype.

ANIMALS

40 dogs with superficial bacterial folliculitis.

PROCEDURES

Samples were obtained from 3 pustules and 3 carriage sites (ie, anus, nonlesional axillary skin, and nasal mucosa) for bacterial culture, morphologic identification, Gram staining, catalase and coagulase testing, antimicrobial susceptibility testing, speciation, and pulsed-field gel electrophoresis (PFGE).

RESULTS

223 isolates from pustules and carriage sites were included. Seventeen susceptibility phenotypes were found among isolates. One hundred twenty-eight (100%) isolates from pustules and 95 (100%) isolates from carriage sites were susceptible to cephalothin; 128 (100%) isolates from pustules and 94 (98.9%) isolates from carriage sites were susceptible to amoxicillin-clavulanic acid; 114 (89.1%) isolates from pustules and 82 (86.3%) isolates from carriage sites were susceptible to erythromycin and lincomycin hydrochloride; and 103 (80.5%) isolates from pustules and 70 (73.7%) isolates from carriage sites were susceptible to trimethoprim-sulfamethoxazole. In 37 of 39 (94.9%) dogs, isolates with the same PFGE pattern from multiple pustules had the same susceptibility phenotype. In 21 of 33 (63.6%) dogs, isolates from multiple carriage sites with the same PFGE pattern had the same susceptibility phenotype.

CONCLUSIONS AND CLINICAL RELEVANCE

In dogs with superficial bacterial folliculitis, most coagulase-positive staphylococcal isolates from pustules that are genotypically the same strain will have the same susceptibility phenotype and treatment may be based on empiric antimicrobial selection or susceptibility testing of 1 lesional isolate.

Folliculitis decalvans of the scalp: response to triple therapy with isotretinoin, clindamycin, and prednisolone

Folliculitis decalvans of the scalp is a recurrent, purulent follicular inflammation leading to scarring alopecia. We report on a 27-year-old man with folliculitis decalvans successfully treated with a combination of isotretinoin, corticosteroids, and clindamycin.

Industrial Pseudomonas folliculitis

INTRODUCTION

Complaints of poor water quality and skin rashes among workers at a US cardboard manufacturing facility were investigated to determine potential causes.

METHODS

Employees were interviewed regarding work duties and health symptoms. Areas of dermatitis in affected employees were visually examined. Collected water samples were tested for potential chemical and microbial contaminants.

RESULTS

A total of 27 employees were identified with complaints of recent skin rashes affecting primarily the upper and lower extremities. Dermatitis complaints were associated with water contact and work in areas with poor water quality. Water testing showed high levels of Pseudomonas aeruginosa. Other tested substances were not at levels of concern.

CONCLUSIONS

Overgrowth of P. aeruginosa occurred in the water system shortly after the facility switched to a closed-loop water recycling system and was the most likely cause of the observed dermatitis. To our knowledge, this is the first reported outbreak of Pseudomonas folliculitis in an industrial setting.

Genotypic relatedness of staphylococcal strains isolated from pustules and carriage sites in dogs with superficial bacterial folliculitis

OBJECTIVE

To determine whether staphylococcal isolates cultured from pustules and carriage sites in dogs with superficial bacterial folliculitis were genotypically the same strain by use of pulsed-field gel electrophoresis (PFGE).

ANIMALS

40 dogs with superficial bacterial folliculitis.

PROCEDURES

Samples were obtained from 3 pustules and 3 carriage sites (anus, axillary skin, and nasal mucosa). Bacterial culture, morphologic identification, Gram staining, catalase and coagulase tests, speciation, and PFGE were performed.

RESULTS

Of 246 isolates, 203 were Staphylococcus intermedius, 5 were Staphylococcus aureus, 15 were Staphylococcusspp, and 22 were coagulase-negative staphylococcal isolates. No dog had an isolate with the same PFGE pattern as an isolate from another dog. Coagulase-positive isolates from multiple pustules and multiple carriage sites had the same PFGE pattern in 37 of 39 (94.9%) and 22 of 39 (56.4%) dogs, respectively. Coagulase-positive staphylococcal isolates from at least 1 pustule had the same PFGE pattern as an isolate from at least 1 carriage site in 34 of 36 (94.4%) dogs. Ninety-seven of 116 (83.6%) coagulase-positive staphylococcal isolates from pustules had the same PFGE pattern as an isolate from at least 1 carriage site. Sixty-nine of 91 (75.8%) coagulase-positive staphylococcal isolates from carriage sites had the same PFGE pattern as an isolate from at least 1 pustule.

CONCLUSIONS AND CLINICAL RELEVANCE

Coagulasepositive staphylococcal strains were heterogeneous among dogs with superficial bacterial folliculitis. In individual dogs, strains from multiple pustules were genotypically the same, and strains from pustules were genotypically the same as strains from carriage sites.

Community-acquired methicillin-resistant Staphylococcus aureus skin infection presenting as a periumbilical folliculitis

Community-acquired methicillin-resistant Staphylococcus aureus (CAMRSA) infection is a clinical problem of increasing global incidence. CAMRSA most commonly presents as abscess and cellulitis of the skin and soft tissue. However, the lesions of cutaneous CAMRSA infection are pleomorphic and may appear as erythematous pustules of superficial folliculitis. This report presents the cases of 2 patients with CAMRSA skin infection that presented as a superficial folliculitis. The distribution of CAMRSA-related, erythematous, folliculocentric pustules was periumbilical, in contrast to the lesional location of methicillin-susceptible S. aureus (MSSA)-associated folliculitis, which typically appears on the axillae, bearded area, buttocks, and extremities. CAMRSA should be considered in the diagnosis of periumbilical folliculitis or superficial folliculitis arising in areas not typically affected by MSSA-related folliculitis, such as the chest, flanks, and scrotum.

[The use of calcofluor white for studying Malassezia species by direct microscopy]

Fungi of Malassezia genus are known as normal flora in human beings. However, different pathologies due to Malassezia, have been described. Traditionally, early diagnosis was delayed because of the difficulties in culture isolation of these organisms. The aim of this work, is to evaluate the technique of observation microscopy with calcofluor, for identification of Malassezia in both, clinical samples and isolates. In comparison to traditional method of direct examination with lactophenol-blue, calcofluor method offers an advantage because it turns easier the observation of fungal elements and its budding pattern. This technique contributes then, to identify species of Malassezia. The analysis of clinical specimens with calcofluor followed by observation under fluorescence microscopy is a simple and rapid method for the identification, and contribute therefore to the early diagnosis.

[Malassezia. Current knowledge and study perspectives]

The study of Malassezia has been postponed for many years due to its nutritional requirements and its morphological variability. Molecular biology methods led to a taxonomic revision of this genus and to a new interest for its clinical importance. Nowadays, 11 Malassezia species are known, 10 are lipophilic, having similar morphological, physiological and biochemical characteristics, therefore, conventional techniques are not useful to differentiating them. Molecular methods are an accurate tool in the identification and they lead to a better knowledge of the ecology and epidemiology of this genus. Noteworthy antifungal susceptibility variations have been observed in some species, although there is not a standard method for these yeasts. There are few data about their biochemical characteristics, and the enzymes they produce might be important virulence factors, favouring host tissue invasion. Malassezia has been recognised as a member of the normal human and animal skin. Its implication in pathologic processes, including skin diseases to systemic infections, is the main issue in current investigations in order to determine the real pathogenic role of these yeasts.

Malassezia Baillon, emerging clinical yeasts

The human and animal pathogenic yeast genus Malassezia has received considerable attention in recent years from dermatologists, other clinicians, veterinarians and mycologists. Some points highlighted in this review include recent advances in the technological developments related to detection, identification, and classification of Malassezia species. The clinical association of Malassezia species with a number of mammalian dermatological diseases including dandruff, seborrhoeic dermatitis, pityriasis versicolor, psoriasis, folliculitis and otitis is also discussed.

Acinetobacter baumanii folliculitis in a patient with AIDS

Gram-negative folliculitis usually involves the face and develops in patients with acne or rosacea during long-term antibiotic therapy. Numerous pathogens have been found, but not, until now, Acinetobacter baumanii which has previously been recognized as an important cause of nosocomial infections and hospital outbreaks. We report here a case of A. baumanii folliculitis of the face, neck, arms and upper part of trunk in a patient with AIDS responding to intravenous treatment with ticarcillin-clavulanic acid. The bacterium was not found on healthy skin and the source of the infection remained unknown.

Malassezia folliculitis on the scalp of a 12-year-old healthy child

Malassezia folliculitis is a condition chracterized by itchy follicular papules and pustules with erythema. Malassezia yeasts are the pathogens in this condition. It is mainly located on the back, shoulders, and chest. Presented here is a 12-year-old boy with malassezia folliculitis on the scalp. The case was found to be worthy of presentation because it rarely occurs in childhood and is rarely located on the scalp.

Pityrosporum folliculitis: diagnosis and management in 6 female adolescents with acne vulgaris

BACKGROUND

Pityrosporum folliculitis is a common inflammatory skin disorder that may mimic acne vulgaris. Some adolescents with recalcitrant follicular pustules or papules may have acne and Pityrosporum folliculitis simultaneously. Clinical response is dependent on treating both conditions.

OBJECTIVES

To demonstrate the similarity in clinical manifestation between acne vulgaris and Pityrosporum folliculitis, the benefit of potassium hydroxide preparation, and the benefit of appropriate antifungal therapy.

PATIENTS

We describe 6 female adolescents with concurrent Pityrosporum folliculitis infection and acne vulgaris.

INTERVENTION

A potassium hydroxide examination was performed on all 6 patients from the exudate of follicular pustules exhibiting spores consistent with yeast. All patients were treated with oral antifungals, and 5 of the 6 patients were also treated with topical antifungals.

RESULTS

Six of 6 patients improved with antifungal treatment. All patients also required some ongoing therapy for their acne.

CONCLUSIONS

These patients demonstrate that follicular papulopustular inflammation of the face, back, and chest may be due to a combination of acne vulgaris and Pityrosporum folliculitis, a common yet less frequently identified disorder. Symptoms often wax and wane depending on the patient's activities, time of the year, current treatment regimens, and other factors. Pityrosporum folliculitis will often worsen with traditional acne therapy and dramatically respond to antifungal therapy.

Skin diseases associated with Malassezia species

The yeasts of the genus Malassezia have been associated with a number of diseases affecting the human skin, such as pityriasis versicolor, Malassezia (Pityrosporum) folliculitis, seborrheic dermatitis and dandruff, atopic dermatitis, psoriasis, and--less commonly--with other dermatologic disorders such as confluent and reticulated papillomatosis, onychomycosis, and transient acantholytic dermatosis. Although Malassezia yeasts are a part of the normal microflora, under certain conditions they can cause superficial skin infection. The study of the clinical role of Malassezia species has been surrounded by controversy because of their fastidious nature in vitro, and relative difficulty in isolation, cultivation, and identification. Many studies have been published in the past few years after the taxonomic revision carried out in 1996 in which 7 species were recognized. Two new species have been recently described, one of which has been isolated from patients with atopic dermatitis. This review focuses on the clinical, mycologic, and immunologic aspects of the various skin diseases associated with Malassezia. It also highlights the importance of individual Malassezia species in the different dermatologic disorders related to these yeasts.

Involvement of granulysin-producing T cells in the development of superficial microbial folliculitis

BACKGROUND

Granulysin is a recently identified antimicrobial protein expressed on cytotoxic T cells, natural killer (NK) cells and NKT cells. It has been shown that granulysin contributes to the defence mechanisms against mycobacterial infection. Superficial microbial folliculitis is a common skin disease. In a previous report, we showed that, as a first line of defence, alpha-defensin, a human neutrophil peptide, and beta-defensin (human beta-defensin-2) were expressed in infiltrating neutrophils and in lesional epidermal keratinocytes, respectively, in superficial folliculitis. As we also observed many infiltrating lymphocytes in lesional dermis, we hypothesized that infiltrating lymphocytes may possess antimicrobial substances, such as granulysin, and play a role in the defence mechanism as a second line of defence.

OBJECTIVES

Seven specimens of superficial microbial folliculitis diagnosed clinically and histologically were examined by means of immunohistochemistry. To identify the phenotype of cells expressing granulysin, confocal laser microscopic examination was performed.

RESULTS

A dense lymphoid cell infiltrate was observed in pustules, in the perivascular regions. A large number of these lymphoid cells were positive for granulysin. Phenotypically, cells consisted of CD3+ T cells, CD8+ T cells and UCHL-1+ T cells. CD20+ cells and CD56+ cells were not observed. Microscopic examination with a confocal laser showed that the lymphocytes producing granulysin were CD3+ and CD4+ T cells but not CD8+ T cells.

CONCLUSIONS

We showed that many granulysin-bearing T cells infiltrated affected follicles and perilesional dermis in superficial microbial folliculitis. However, few granulysin-positive lymphoid cells were observed in sterile pustular lesions. Our observations indicated that adaptive immunity such as granulysin, a lymphocyte-produced antimicrobial protein, may play an important role in the cutaneous defence mechanism.

Treatment of gram-negative folliculitis in patients with acne

Gram-negative folliculitis may be the result of long-term antibacterial treatment in acne patients. It is caused by bacterial interference and replacement of the Gram-positive flora of the facial skin and the mucous membranes of the nose and infestation with Gram-negative bacteria. These Gram-negative bacteria include Escherischia coli, Pseudomonas aeruginosa, Serratia marescens, Klebsiella and Proteus mirabilis. The occurrence of Gram-negative folliculitis should be considered in acne patients in whom oral treatment with tetracyclines has not resulted in a significant improvement of acne lesions after 3-6 months' treatment. The occurrence of Gram-negative folliculitis in acne patients is believed to be generally underestimated, since correct sampling and bacteriology is rarely performed by clinicians. Gram-negative folliculitis in acne and rosacea patients is best treated with isotretinoin (0.5-1 mg/kg daily for 4-5 months).

[Malassezia species isolated from skin diseases in a care center in the city of Buenos Aires, Argentina]

The epidemiology of Malassezia genus is poorly understood; geographical and population factors might have influence on the species distribution. The aim of this work was to determine the frequency of Malassezia species involved in skin diseases in a diagnostic center at Buenos Aires City. From 02/01/1999 to 10/31/2001, 456 skin specimens from 447 patients diagnosed as pityriasis versicolor, seborrheic dermatitis, foliculitis and atopic dermatitis, were analyzed by microscopic examination and culture. Malassezia spp was evidenced in 255 skin samples (55.9%) by microscopic analysis but it could be recovered from only 99 (38.8%) specimens. Malassezia species were isolated from 10 (3.9%) scarring lesions that were negative by microscopy. Among 109 isolates, M. sympodialis (58.7%) was the most frequent, followed by M. globosa and M. furfur (18.3% and 9.2%). Unique isolates (0.9%) of M. obtusa, M. slooffiae and M. restricta were recovered. Eleven isolates (10.1%) could not be identified because they had lost viability in the culture. This is the first study on Malassezia species associated to skin diseases in Argentina; further screening including other geographic regions of the country is necessary in order to confirm these results.