Position statement: Recommendations on the diagnosis and treatment of Malassezia folliculitis.

Malassezia is a lipophilic yeast that is a part of the human mycobiome. Malassezia folliculitis appears when the benign colonization of the hair follicles, by the Malassezia yeasts, becomes symptomatic with pruritic papules and pustules. Although Malassezia folliculitis is common in hospital departments, diagnosing and treating it varies among dermatologists and countries. The European Academy of Dermatology and Venereology Mycology Task Force Malassezia folliculitis working group has, therefore, sought to develop these recommendations for the diagnosis and management of Malassezia folliculitis. Recommendations comprise methods for diagnosing Malassezia folliculitis, required positive findings before starting therapies and specific treatment algorithms for individuals who are immunocompetent, immunocompromised or who have compromised liver function. In conclusion, this study provides a clinical strategy for diagnosing and managing Malassezia folliculitis.

Critical synthesis of available data in Malassezia folliculitis and a systematic review of treatments.

Folliculitis is an inflammatory process involving the hair follicle, frequently attributed to infectious causes. Malassezia, an established symbiotic yeast that can evolve to a skin pathogen with opportunistic attributes, is a common source of folliculitis, especially when intrinsic (e.g. immunosuppression) or extrinsic (high ambient temperature and humidity, clothing) impact on the hair follicle and the overlying skin microenvironment. Our aim was to critically review the pathophysiology and clinical characteristics of Malassezia folliculitis, to describe laboratory methods that facilitate diagnosis and to systematically review treatment options. Malassezia folliculitis manifests as a pruritic, follicular papulopustular eruption distributed on the upper trunk. It commonly affects young to middle-aged adults and immunosuppressed individuals. Inclusion into the differential diagnosis of folliculitis is regularly oversighted, and the prerequisite-targeted diagnostic procedures are not always performed. Sampling by tape stripping or comedo extractor and microscopic examination of the sample usually identifies the monopolar budding yeast cells of Malassezia without the presence of hyphae. However, confirmation of the diagnosis with anatomical association with the hair follicle is performed by biopsy. For systematic review of therapies, PubMed was searched using the search string "(malassezia" [MeSH Terms] OR "malassezia" [All Fields] OR pityrosporum [All Fields]) AND "folliculitis" [MeSH Terms] and EMBASE was searched using the search string: 'malassezia folliculitis.mp OR pityrosporum folliculitis.mp'. In total, 28 full-length studies were assessed for eligibility and 21 were selected for inclusion in therapy evaluation. Conclusively Malassezia folliculitis should be considered in the assessment of truncal, follicular skin lesions. Patient's history, comorbidities and clinical presentation are usually indicative, but microscopically and histological examination is needed to confirm the diagnosis. Adequate samples obtained with comedo extractor and serial sections in the histological material are critical for proper diagnosis. Therapy should include systemic or topical measures for the control of the inflammation, as well as the prevention of recurrences.

A survey among dermatologists: diagnostics of superficial fungal infections - what is used and what is needed to initiate therapy and assess efficacy?

BACKGROUND: Superficial fungal infections are common. It is important to confirm the clinical diagnosis by mycological laboratory methods before initiating systemic antifungal treatment, especially as antifungal sensitivity and in vitro susceptibility may differ between different genera and species. For many years, the gold standard for diagnosis of superficial fungal infections has been direct fungal detection in the clinical specimen (microscopy) supplemented by culturing. Lately, newer molecular based methods for fungal identification have been developed. OBJECTIVE: This study was initiated to focus on the current usage of mycological diagnostics for superficial fungal infections by dermatologists. It was designed to investigate whether it was necessary to differentiate between initial diagnostic tests and those used at treatment follow-up in specific superficial fungal infections. METHODS: An online questionnaire was distributed among members of the EADV mycology Task Force and other dermatologists with a special interest in mycology and nail disease. RESULTS: The survey was distributed to 62 dermatologists of whom 38 (61%) completed the whole survey, 7 (11%) partially completed and 17 (27%) did not respond. Nearly, all respondents (82-100%) said that ideally they would use the result of direct microscopy (or histology) combined with a genus/species directed treatment of onychomycosis, dermatophytosis, Candida- and Malassezia-related infections. The majority of the dermatologists used a combination of clinical assessment and direct microscopy for treatment assessment and the viability of the fungus was considered more important at this visit than when initiating the treatment. Molecular based methods were not available for all responders. CONCLUSION: The available diagnostic methods are heterogeneous and their usage differs between different practices as well as between countries. The survey confirmed that dermatologists find it important to make a mycological diagnosis, particularly prior to starting oral antifungal treatment in order to confirm the diagnose and target the therapy according to genus and species.

Aerosolized spread of bacteria and reduction of bacterial wound contamination with three different methods of surgical wound debridement: a pilot study.

BACKGROUND: Debridement is essential in wound treatment to remove necrotic tissue and wound bacteria, but may lead to the transmission of bacteria by aerosolization. AIM: To investigate bacterial transmission and wound bacterial reduction induced by debridement using a cold steel curette, plasma-mediated bipolar radiofrequency ablation (Coblation(®)) or hydrodebridement (Versajet(®)) using a wound model inoculated with Staphylococcus aureus. METHODS: A full-thickness dermal wound was created in fresh porcine joint specimens, inoculated with S. aureus and incubated at 37°C for 24h. The specimens were surgically debrided with a curette, Coblation or Versajet, or were left untreated. During and after each debridement, aerosolized bacteria were measured by active and passive sampling. To assess the bacterial load of the wound, three quantitative swabs and one cylinder scrub sample were taken from each wound at baseline, post incubation and post debridement. FINDINGS: Versajet debridement resulted in significant bacterial aerosolization, but this was not the case when using a curette or Coblation. Only Coblation was able to reduce the bacterial load of the wound significantly. CONCLUSION: Extra protective means should be implemented when using Versajet debridement for infected and colonized wounds. The same precautions may be less essential when using a curette or Coblation.

Efficacious and safe management of moderate to severe scalp seborrhoeic dermatitis using clobetasol propionate shampoo 0·05% combined with ketoconazole shampoo 2%: a randomized, controlled study.

BACKGROUND: Topical antifungals and corticosteroids are the mainstay of treatment for seborrhoeic dermatitis. The short-contact clobetasol propionate 0·05% shampoo (CP) is an efficacious and safe once-daily treatment for scalp psoriasis. OBJECTIVES: To evaluate the efficacy and safety of CP alone and combined with ketoconazole shampoo 2% (KC) in the treatment of moderate to severe scalp seborrhoeic dermatitis. METHODS: This randomized and investigator-blinded study consisted of three phases, each lasting 4 weeks. During the treatment phase, subjects were randomized to receive KC twice weekly (K2), CP twice weekly (C2), CP twice weekly alternating with KC twice weekly (C2 + K2) or CP four times weekly alternating with KC twice weekly (C4+K2). All subjects received KC once weekly during the maintenance phase and were untreated during the follow-up phase. RESULTS: At the end of the treatment phase, all three CP-containing regimens were significantly more efficacious than K2 in decreasing the overall disease severity (P < 0·05). Both combination regimens were also significantly more efficacious than K2 in decreasing each individual sign of the disease (P < 0·05). While the C2 and C4 + K2 groups experienced slight worsening during the maintenance phase, the efficacy of C2 + K2 was sustained and remained the highest among all groups. All regimens were well tolerated without inducing any skin atrophy. Similarly low incidences of telangiectasia, burning and adverse events were observed among the four groups. CONCLUSIONS: The combination therapy of twice-weekly CP alternating with twice-weekly KC provided significantly greater efficacy than KC alone and a sustained effect in the treatment of moderate to severe scalp seborrhoeic dermatitis.

Bathing and cleansing in newborns from day 1 to first year of life: recommendations from a European round table meeting.

BACKGROUND: Development of the skin barrier continues up to 12 months after birth; therefore, care must be taken when cleansing and bathing infants' skin. Available guidelines for skin care in newborns are, however, limited. In 2007, the 1st European Round Table meeting on 'Best Practice for Infant Cleansing' was held, at which a panel of expert dermatologists and paediatricians from across Europe aimed to provide a consensus on infant bathing and cleansing. OUTCOMES: Based on discussions at the meeting and a comprehensive literature review, the panel developed a series of recommendations relating to several aspects of infant skin care, including initial and routine bathing, safety while bathing, and post-bathing procedures. The panel also focused on the use of liquid cleansers in bathing, particularly relating to the benefits of liquid cleansers over water alone, and the criteria that should be used when choosing an appropriate liquid cleanser for infants. Alkaline soaps have numerous disadvantages compared with liquid cleansers, with effects on skin pH and lipid content, as well as causing skin drying and irritation. Liquid cleansers used in newborns should have documented evidence of their mildness on skin and eyes, and those containing an emollient may have further benefits. Finally, the panel discussed seasonal differences in skin care, and issues relating to infants at high risk of atopic dermatitis. The panel further discussed the need of clinical studies to investigate the impact of liquid cleansers on skin physiology parameters on newborns' and infants' skin. CONCLUSIONS: Bathing is generally superior to washing, provided basic safety procedures are followed, and has psychological benefits for the infant and parents. When bathing infants with a liquid cleanser, a mild one not altering the normal pH of the skin surface or causing irritation to skin or eyes should be chosen.

A randomized controlled trial of R-salbutamol for topical treatment of discoid lupus erythematosus.

BACKGROUND: In a recent open pilot trial, R-salbutamol sulphate, a well-known molecule with anti-inflammatory effects, was tested successfully on patients with therapy-resistant discoid lupus erythematosus (DLE). OBJECTIVES: To compare the efficacy and safety of R-salbutamol cream 0.5% vs. placebo on DLE lesions in a multicentre, double-blinded, randomized, placebo-controlled phase II trial. METHODS: Thirty-seven patients with at least one newly developed DLE lesion were randomized - 19 to the R-salbutamol cream 0.5% and 18 to placebo - and treated twice daily for 8 weeks. Efficacy was evaluated through scores of erythema, scaling/hypertrophy and induration as well as pain and itching; general improvement scored by the investigator and global improvement scored by patients' assessment were also evaluated. RESULTS: The mean area under the curve of improvement for scaling/hypertrophy, pain, itching and global patient assessment was significantly better for the actively treated patients as compared with placebo (scaling/hypertrophy, P = 0.0262; pain, P = 0.0238; itching, P = 0.0135; global patient assessment, P = 0.045). Moreover, the percentage of patients without induration was significantly higher in the active group compared with the placebo group (P = 0.013), and a statistically significantly greater decrease in the size of the lesional area was also seen in the overall analysis of the R-salbutamol-treated patients (P = 0.0197). No serious adverse events were reported. CONCLUSIONS: Application of R-salbutamol cream 0.5% was safe and well tolerated. Statistically significant effects were seen on scaling/hypertrophy, induration, pain and itching as well as patient global assessment, suggesting that R-salbutamol could be a promising new topical therapy alternative for DLE.

A multicentre, randomized, controlled study of the efficacy, safety and cost-effectiveness of a combination therapy with amorolfine nail lacquer and oral terbinafine compared with oral terbinafine alone for the treatment of onychomycosis with matrix involvement.

BACKGROUND: Onychomycosis is common, accounting for up to 50% of all nail disorders. Toenail onychomycosis can cause nail deformity, embarrassment, pain and walking difficulties. Some populations, such as individuals with diabetes, are at higher risk for developing secondary complications such as infections. Treatment takes many months and therapeutic choices can increase clinical effectiveness, lower toxicity and minimize healthcare costs. OBJECTIVES: Based on the results of a previous pilot study, the objective of the present study was to show, in a larger population, the enhanced efficacy of a combination of amorolfine nail lacquer and oral terbinafine in the treatment of onychomycosis with matrix involvement. In addition, a cost-effectiveness analysis was performed. METHODS: In this multicentre, randomized, open-label, parallel group study, patients were randomized to receive either a combination of amorolfine hydrochloride 5% nail lacquer once weekly for 12 months plus terbinafine 250 mg once daily for 3 months (AT group) or terbinafine alone once daily for 3 months (T group). The study duration was 18 months including a 6-month treatment-free phase following the 12-month active treatment phase for the AT group and a 15-month treatment-free phase following the 3-month active treatment phase for the T group. The primary efficacy criterion was overall response, dichotomized into success or failure, success being the combination of clinical cure and negative mycology at month 18. This criterion was used as the effectiveness measure in the pharmacoeconomic analysis, conducted from a payer perspective. RESULTS: In total, 249 patients were included into the study: 120 in the AT group and 129 in the T group. A significantly higher success rate was observed for patients in the AT group relative to those in the T group at 18 months (59.2% vs. 45.0%; P = 0.03). Both treatment regimens were safe and well tolerated. Treatment cost per cured patient was lower for the combination than for terbinafine alone in all countries. CONCLUSIONS: Study results confirmed that, in the treatment of dermatophytic toenail onychomycosis with matrix involvement, amorolfine nail lacquer in combination with oral terbinafine enhances clinical efficacy and is more cost-effective than terbinafine alone.

Genetic predisposition--understanding underlying mechanisms of onychomycosis.

BACKGROUND: There are numerous factors that predispose to onychomycosis including genetic predisposition, diabetes mellitus, immunosuppression, vascular disease and psoriasis. OBJECTIVES: The aims of this workshop were to discuss current knowledge of genetic risk factors and the approaches that should be used to investigate underlying mechanisms. RESULTS: The high prevalence of onychomycosis within certain families was initially attributed to intrafamilial transmission. However, the low prevalence of infection in people marrying into infected families together with the high prevalence among their offspring suggested a genetic basis. The state-of-the-art pedigree study by Zaias et al. suggested that Trichophyton rubrum infection shows an autosomal dominant pattern of inheritance. A consensus was reached that epidemiological and genetic studies are required to investigate this issue further. For epidemiological studies, families in which two or three generations are infected with T. rubrum should be selected. Patients with T. rubrum on different body sites should be included, and the presence of associated diseases or other common features in these individuals should be investigated to identify trigger factors. CONCLUSION: Genetic studies should explore the mode of inheritance of onychomycosis and look for the disease gene(s). Serum samples from patients and age-sex matched controls must be analysed centrally. The results of these studies will make it possible to develop therapeutic, preventive and prophylatic measures and to provide patients and their families with information.

Clinical trial design--towards better practices.

OBJECTIVES: To review methodological approaches used in recent publications in onychomycosis clinical research. To identify key methodological criteria to ensure conclusive and reliable clinical results. METHODS: A Medline search for recent articles on onychomycosis treatment revealed considerable variation in inclusion criteria, definitions and methodology, rendering comparisons difficult. RESULTS: Careful diagnosis at trial entry is critical and predisposing factors affecting overall results are rarely considered at enrolment. Clear definitions are required, notably for the terms mycological, clinical and total cure. A consensus was reached that only studies that are evidence-based, controlled and double-blind with less than 10-15% of patients lost to follow-up should be accepted. Results should be interpreted with caution if a given treatment is found to be less effective than previously reported, even if the results are published in a recognized journal. It was agreed that an explanatory/pilot study should be done initially to determine whether there is a reason to believe that a new therapy is effective. If promising results are obtained, a double-blind, randomized study comparing the new therapy with either an existing therapy (preferably) or a placebo may be initiated. CONCLUSIONS: Sample size, and inclusion and exclusion criteria should be clearly determined. Efficacy criteria should include mycological, clinical and total cure rates. Finally, studies of toenail and fingernail onychomycosis must last at least 18 and 9 months, respectively.

Pedal dermatophyte infection in psoriasis.

BACKGROUND: Dermatophyte infections have been considered rare in psoriasis. However, there are data indicating that tinea unguium is as common or even more common in psoriasis compared with healthy controls. Tinea unguium is generally a secondary event to tinea pedis infection. OBJECTIVES: To study the prevalence of tinea pedis and tinea unguium in psoriasis compared with a control group. METHODS: Consecutive psoriasis outpatients aged 18-64 years attending a department of dermatology were examined. Samples for direct microscopy and culture were taken from the interdigital spaces, soles and toenails. Consecutive patients without signs of psoriasis or atopic dermatitis seeking examination of moles constituted the control group. RESULTS: In total, 239 patients with psoriasis and 245 control patients were studied. The prevalence of tinea pedis was 8.8%[95% confidence interval (CI) +/- 3.6%] in the psoriasis group and 7.8% (95% CI +/- 3.4%) in the control group. The corresponding figures for prevalence of tinea unguium were 4.6% (95% CI +/- 2.7%) and 2.4% (95% CI +/- 1.9%), respectively. The differences found in the psoriasis vs. the control groups were not statistically significant. CONCLUSIONS: This study does not support the hypothesis that the prevalence of tinea pedis and tinea unguium in patients with psoriasis differs from that in a normal population.

Prognosis and prognostic factors in adult patients with atopic dermatitis: a long-term follow-up questionnaire study.

BACKGROUND: Atopic dermatitis (AD) is a chronic relapsing skin disease. Several investigations concerning the long-term prognosis of AD among children and teenagers have been performed but there are only few data among adults. OBJECTIVES: To investigate the prognosis and prognostic factors in adult patients with AD by a long-term follow-up (25-38 years). The prognostic factors were defined as those factors of importance for the persistence of AD. PATIENTS AND METHODS: A follow-up questionnaire was sent in November/December 1998 to 922 AD patients examined in our outpatient clinic between 1960 and 1973 among 1366 registered patients with AD. The patients were aged 20 years or older when they visited the clinic and 45 years or older when they answered the follow-up questionnaire. RESULTS: The response rate was 90.4%. The age range at the time of follow-up was 45-86 years (mean 55 years). Of the 833 patients who responded, 59% reported AD at some time during the last 12 months, which we defined as persistent AD. The mean value of clearance rate per person-years was 18%. One of the most important factors associated with persistence of AD was a head and neck dermatitis with or without other AD locations at the time of examination according to the old patient records. CONCLUSIONS: This study showed that the majority of adults with AD still had AD when they became older. This applies particularly if negative prognostic factors existed.

Epidemiology, clinical presentation and diagnosis of onychomycosis.

Onychomycosis is a common nail disease, responsible for up to 50% of diseases of the nail. The distribution of different pathogens is not uniform; it depends on various factors such as climate, geography and migration. However, studies have revealed that two dermatophytes, Trichophyton rubrum and Trichophyton mentagrophytes, account for more than 90% of onychomycoses. Onychomycosis can be divided into four major clinical presentations: distal subungal (the most common form of the disease), proximal subungal (the most common form found in patients with human immunodeficiency virus infection), and superficial and total dystrophic onychomycosis. Onychomycosis is a multifactorial disease. Age has a very important effect on the occurrence of onychomycosis, with a correlation between increasing age and infection. Genetics has also been identified as a factor governing the epidemiology of onychomycosis; T. rubrum infection shows a familial pattern of autosomal dominant inheritance. Disease and lifestyle may also play a role in the epidemiology of fungal nail infections. Studies have shown that diabetes, acquired immunodeficiency syndrome and peripheral arterial disease may be independent predictors of onychomycosis. Because of the multifactorial nature of the epidemiology, accurate diagnosis, pertinent treatment and patient education must be paramount when treating the disease.

Atopy patch test reactions to Malassezia allergens differentiate subgroups of atopic dermatitis patients.

BACKGROUND: The yeast Malassezia is considered to be one of the factors that can contribute to atopic dermatitis (AD). OBJECTIVES: To investigate the reactivity to Malassezia allergens, measured as specific serum IgE, positive skin prick test and positive atopy patch test (APT), in adult patients with AD. METHODS: In total, 132 adult patients with AD, 14 with seborrhoeic dermatitis (SD) and 33 healthy controls were investigated for their reactions to M. sympodialis extract and three recombinant Malassezia allergens (rMal s 1, rMal s 5 and rMal s 6). RESULTS: Sixty-seven per cent of the AD patients, but only one of the SD patients and none of the healthy controls, showed a positive reaction to at least one of the Malassezia allergens (extract and/or recombinant allergens) in at least one of the tests. The levels of M. sympodialis-specific IgE in serum correlated with the total serum IgE levels. Elevated serum levels of M. sympodialis-specific IgE were found in 55% and positive APT reactions in 41% of the AD patients with head and neck dermatitis. A relatively high proportion of patients without head and neck dermatitis and patients with low total serum IgE levels had a positive APT for M. sympodialis, despite lower proportions of individuals with M. sympodialis-specific IgE among these groups of patients. CONCLUSIONS: These results support that Malassezia can play a role in eliciting and maintaining eczema in patients with AD. The addition of an APT to the test battery used in this study reveals a previously overlooked impact of Malassezia hypersensitivity in certain subgroups of AD patients.

Quantitative culture of Malassezia species from different body sites of individuals with or without dermatoses.

Quantitative cultures were obtained using contact plates to determine whether the quantity and composition of Malassezia species at a given anatomic site in normal individuals differs from that of patients with various cutaneous dermatoses. The sample included 20 clinically healthy individuals (without any dermatosis) and 110 patients with dermatoses (including 31 with atopic dermatitis [AD], 28 with psoriasis [PS], 28 with seborrheic dermatitis [SD] and 23 with pityriasis versicolor [PV]). Contact plates filled with special culture medium were used to obtain a quantitative culture from five body sites (scalp, forehead, arm, trunk and leg) of every individual. The number of cfu were recorded for every plate that grew Malassezia yeasts, and 3-5 colonies were isolated for identification to species level using microscopic, physiological and molecular characteristics. The mean cfu counts observed among patients with AD, PS and SD was significantly lower than normal control subjects (P < 0.05). The mean cfu counts from PV patients was not different from that of healthy control subjects. Overall, for all conditions considered together, the mean cfu counts in lesional sites were significantly lower than in non-lesional sites (P <0.05). Furthermore, the mean cfu counts from lesional sites in patients with AD and PS were significantly lower than the corresponding value in patients with PV (P <0.05). Six Malassezia species were recovered from the different dermatoses. Malassezia sympodialis was the most common species associated with AD and PV patients and healthy control subjects, while M. globosa was most frequently isolated from PS and SD patients. More than one Malassezia species was recovered at any given anatomic site from both controls as well as individuals with dermatoses. M. globosa was equally likely to be recovered from scalp, forehead and trunk, but less likely to derive from arms and legs. M. restricta and M. slooffiae were recovered more frequently from the upper body (scalp and forehead) than from the lower body. Among normal individuals and for patients with AD and PV, M. sympodialis was significantly more likely to affect the forehead than the legs.

Epidemiology of Malassezia yeasts associated with pityriasis versicolor in Ontario, Canada.

The genus Malassezia was recently revised to include seven species, but the clinical significance of each of these species is not clearly understood. To obtain a better understanding of the contribution of individual Malassezia species to the epidemiology of pityriasis (tinea) versicolor, we used Leeming-Notman medium to culture patient skin specimens showing positive evidence of Malassezia infection in direct microscopy. Isolates were identified on the basis of recently published morphological and physiological tests for distinction of the new species. Identification using recently developed molecular criteria was also carried out for the ambiguous cases. Malassezia species were cultured from 111 cases of pityriasis versicolor in the Canadian province of Ontario. The most frequently isolated species were Malassezia sympodialis, M. globosa and M. furfur which respectively made up 59.4%, 25.2% and 10.8% of the isolated etiological agents. M. globosa was commonly isolated from a small number of pityriasis versicolor specimens obtained from investigators outside Canada. A large number of additional Ontario specimens with positive direct microscopy failed to yield a culture; however, it is suggested that this is consistent with the standard sampling practice of scraping the older portions of pityriasis lesions rather than the margins, where viable fungal cells are most likely to occur.

Seborrhoeic dermatitis and Pityrosporum (Malassezia) folliculitis: characterization of inflammatory cells and mediators in the skin by immunohistochemistry.

BACKGROUND: The fact that Pityrosporum ovale plays a part in seborrhoeic dermatitis is well established but the mechanism of this relationship has not been established. OBJECTIVES: To compare the number and type of inflammatory cells and mediators in skin biopsies from normal and lesional skin from the trunk and scalp in patients with seborrhoeic dermatitis, Pityrosporum (Malassezia) folliculitis and in normal skin from healthy controls. METHODS: The skin biopsies were stained using the labelled Streptavidin-biotin METHOD: The following markers were studied: CD4, CD8, CD68, HLA-DR, NK1, CD16, C1q, C3c, IgG, CD54 (ICAM-1), interleukin (IL) -1alpha, IL-1beta, IL-2, IL-4, IL-6, IL-10, IL-12, tumour necrosis factor-alpha and interferon-gamma. RESULTS: HLA-DR+ cells were seen in the highest number, and were higher in lesional skin compared with normal skin from both patients and healthy volunteers. ICAM-1 expression was also increased in lesional skin. C1q and the interleukins showed an increased cellular and intercellular staining in patients compared with healthy controls and the intercellular staining was often more intense in lesions compared with non-lesional skin. Staining was often more intense when Malassezia (Pityrosporum ovale) yeast cells were present. CONCLUSIONS: An increase in NK1+ and CD16+ cells in combination with complement activation indicates that an irritant non-immunogenic stimulation of the immune system is important. The result with the interleukins showed both an increase in the production of inflammatory interleukins as well as in the regulatory interleukins for both TH1 and TH2 cells. Similarities to the immune response described for Candida albicans infections indicate the role of Malassezia in the skin response in seborrhoeic dermatitis and Pityrosporum folliculitis.

In vitro susceptibility of the seven Malassezia species to ketoconazole, voriconazole, itraconazole and terbinafine.

Fifty-five strains, either authentic or ex-type, of seven Malassezia species were investigated for in vitro susceptibility to various concentrations (0.03-64.0 microg/mL) of three azole drugs, ketoconazole, voriconazole and itraconazole, as well as the allylamine terbinafine, using the agar dilution method. All strains of the seven Malassezia species were susceptible to the three azole drugs at low concentrations. M. furfur, M. sympodialis, M. slooffiae, M. pachydermatis, M. globosa, M. obtusa and M. restricta were most sensitive to ketoconazole and itraconazole, with minimum inhibitory concentrations (MICs) ranging from < or = 0.03 to 0.125 microg/mL. The recently introduced antifungal, voriconazole, was also very effective, with MIC80 values < or = 0.03 microg/mL for 80% of strains. MICs of terbinafine against the seven Malassezia species ranged from