Quantitative evaluation of dermatological antiseptics.

Topical antiseptics are frequently used in dermatological management, yet evidence for the efficacy of traditional generic formulations is often largely anecdotal. We tested the in vitro bactericidal activity of four commonly used topical antiseptics against Staphylococcus aureus, using a modified version of the European Standard EN 1276, a quantitative suspension test for evaluation of the bactericidal activity of chemical disinfectants and antiseptics. To meet the standard for antiseptic effectiveness of EN 1276, at least a 5 log10 reduction in bacterial count within 5 minutes of exposure is required. While 1% benzalkonium chloride and 6% hydrogen peroxide both achieved a 5 log10 reduction in S. aureus count, neither 2% aqueous eosin nor 1 : 10 000 potassium permanganate showed significant bactericidal activity compared with control at exposure periods of up to 1 h. Aqueous eosin and potassium permanganate may have desirable astringent properties, but these results suggest they lack effective antiseptic activity, at least against S. aureus.

Cutaneous Mycobacterium chelonae infection in Edinburgh and the Lothians, South-East Scotland, U.K.

BACKGROUND: We reviewed all cases of Mycobacterium chelonae infection seen in our department between 1 January 2008 and 31 December 2012. OBJECTIVES: To review the epidemiology, clinical features and management of cutaneous M. chelonae in South-East Scotland, and to compare prevalence data with the rest of Scotland. METHODS: The Scottish Mycobacteria Reference Laboratory database was searched for all cases of cutaneous mycobacterial infections. RESULTS: One hundred and thirty-four cases of cutaneous mycobacterial infection were recorded. Sixty-three were tuberculous; of the remaining 71, M. chelonae was the most common nontuberculous organism (27 cases). National Health Service (NHS) Lothian Health Board was the area with highest incidence in the Scotland (12 cases). Three main groups of patients in the NHS Lothian Health Board contracted M. chelonae: immunosuppressed patients (n = 6); those who had undergone tattooing (n = 4); and others (n = 2). One case is, we believe, the first report of M. chelonae cutaneous infection associated with topical corticosteroid immunosuppression. The majority of patients were treated with clarithromycin monotherapy. CONCLUSION: The most prevalent nontuberculous cutaneous mycobacterial organism in Scotland is M. chelonae. The prevalence of M. chelonae in Edinburgh and the Lothians compared with the rest of Scotland is disproportionately high, possibly owing to increased local awareness and established facilities for mycobacterial studies. Immunosuppression with prednisolone appears to be a major risk factor. The first outbreak of tattoo-related M. chelonae infection in the U.K. has been reported. Clinicians should be aware of mycobacterial cutaneous infection and ensure that diagnostic skin samples are cultured at the optimal temperatures.

Mycobacterium chelonae infection: a complication of tattooing.

We describe an outbreak of Mycobacterium chelonae infection in four young immunocompetent patients who were tattooed by the same artist. All had been previously tattooed without complication, but following the latest tattooing session, they all developed a very similar papular eruption confined to skin that had been newly coloured light grey. On histological examination of the eruption, granulomatous inflammation with microabscess formation was seen, in association with the tattoo pigment. Skin cultures grown under optimal conditions grew M. chelonae, sensitive to clarithromycin, from one patient. M. chelonae was also cultured from the contents and nozzle of an opened bottle of light-grey ink from the tattoo parlour frequented by the patients. Dermatologists should consider mycobacterial infection in patients who develop inflammatory changes within a new tattoo.

Missing links: Weber-Cockayne keratin mutations implicate the L12 linker domain in effective cytoskeleton function.

We have identified mutations in keratins K5 (Arg331Cys) and K14 (Val270Met) in two kinships affected by the dominantly-inherited skin blistering disease, Weber-Cockayne epidermolysis bullosa simplex (EBS-WC). Linkage analysis, DNA sequencing and clinical and ultrastructural analysis are combined to provide the first detailed description of classical EBS-WC. Both phenotypes show similar blistering on trauma, indicating that both mutations compromise the structural resilience of the basal keratinocytes by affecting the keratin cytoskeleton. The location of these mutations in the L12 linker, which bisects the alpha-helical rod region of intermediate filament proteins, identifies another keratin mutation cluster leading to hereditary skin fragility syndromes.

The profile of dermatological problems in primary care.

BACKGROUND: Cutaneous disease is thought to account for 10-15% of patient consultations with general practitioners, but relatively little is known about the demography of dermatological conditions in primary care. AIM: To assess the proportion and diagnostic profile of dermatological conditions seen in primary care in the southeast of Scotland, and to draw comparisons with secondary dermatological care. METHODS: General practitioners in 13 general practices were asked to note all skin-related consultations during a 2-week period. The case notes of these patients were reviewed, and diagnosis and treatment was recorded. Patients who had consulted for the same skin disorder on >or= 3 occasions during the previous year were invited for assessment by a consultant dermatologist. Where possible, the case notes from 10% of all consultations during the 2-week study period were examined to assess accuracy of recording. RESULTS: The percentage of consultations relating to cutaneous disorders varied between practices, ranging from 3% to 18.8%, with a mean of 8.4%. Eczema accounted for 22.5%, infections 20.3% and benign tumours for 11.4% of consultations with a dermatological basis. In contrast, in secondary care, benign tumours accounted for 23.8%, malignant tumours for 16.4% and eczema for 16.3% of dermatological consultations. CONCLUSIONS: Dermatological disorders make up a significant proportion of general practitioners' workload. The diagnostic profile of primary-care dermatology differs markedly from that of hospital practice. General practitioners may benefit from training specifically tailored to the common primary-care dermatological conditions.

The changing face of dermatological practice: 25 years' experience.

BACKGROUND: In order to plan appropriate delivery of dermatology services we need periodically to assess the type of work we undertake and to examine changing trends in the numbers and type of referrals and the workload these referrals generate. OBJECTIVES: To quantify outpatient workload in hospital-based and private practice; to assess reasons for referral to secondary care and to examine the changes over 25 years in the diagnostic spectrum of conditions referred. METHODS: During November 2005, all outpatient dermatological consultations in the south-east of Scotland were recorded. Demographic data, source of and reason for referral, diagnoses, investigations performed, treatment administered and disposal were recorded, and comparisons made with four previous studies. RESULTS: During the 1-month study, attendances were recorded for 2118 new and 2796 review patients (new/review 1 : 1.3, female/male 1.3 : 1, age range 0-106 years). Eighty-nine per cent of new referrals came from primary care and 11% from secondary care. Fifty-seven per cent of referrals were for diagnosis and 38% for management advice. Benign tumours accounted for 33.4%, malignant tumours 11.6%, eczema 16% and psoriasis 7.4% of new cases. For return patients, 20% had skin cancer, 16.5% eczema, 13.4% psoriasis and 9% acne. The referral rate has risen over 25 years from 12.6 per 1000 population in 1980 to 21 per 1000 in 2005, with secondary care referrals increasing from 61 in November 1980 to 230 in November 2005. CONCLUSIONS: Attendances for benign and malignant skin tumours have increased sixfold since 1980. Patients with eczema and psoriasis account for one third of clinic visits. New referrals have risen by 67%, with those from other hospital specialties almost quadrupling since 1980 to 11% of the total in 2005. These results confirm the demand from both primary and secondary care for a specialist dermatology service.

Lipoatrophy with human insulin.

We describe a case of lipoatrophy that was secondary to human insulin. The patient had only ever been treated with human insulin, and the lipoatrophy appeared to partially resolve with continued use of the same insulin preparations. Possible underlying pathogenic mechanisms are discussed.

Hemidesmosome heterogeneity in junctional epidermolysis bullosa revealed by morphometric analysis.

In order to examine the claim for a numerical and structural abnormality of the hemidesmosomes in junctional epidermolysis bullosa (JEB), a morphometric analysis of unseparated dermal-epidermal junction was undertaken in 11 subjects with JEB. Of these, 5 died in infancy with "lethal" disease, 3 were children still alive at 1-6 years with "indeterminate" disease, and 3 were females aged 20-60 years with variable phenotypic expression of "nonlethal" JEB. All the lethal cases had reduced numbers of hemidesmosomes which were small and lacked normal subbasal dense plates, with the exception of 1 patient whose hemidesmosomes were structurally and numerically normal. The principal hemidesmosome abnormality in the 3 cases with indeterminate JEB was the absence of normal subbasal dense plates. In 2 of the 3 cases of nonlethal JEB, the hemidesmosomes appeared normal, whereas in the third patient they showed a similar abnormality to that present in the majority of the lethal group. These results demonstrate that JEB is an ultrastructurally heterogeneous condition, and suggest that, even though the hemidesmosome abnormalities may be of diagnostic value, they do not correlate sufficiently well with the clinical outcome to be useful as a prognostic indicator.

Ultrastructural morphometry of normal human dermal-epidermal junction. The influence of age, sex, and body region on laminar and nonlaminar components.

To obtain baseline data for future studies on such processes as wound healing, carcinogenesis, and blistering, a morphometric analysis of the dermal-epidermal junction was undertaken on normal skin from 3 or 4 standard sites on the arm and leg of 12 subjects aged 20-60 years. Lamina densa was thinner in females than in males (p less than 0.01) but no sex difference was apparent for lamina lucida. Both laminar elements were thinner beneath melanocytes than beneath keratinocytes. Sex, age, and body region had no apparent influence on numbers of hemidesmosomes or basal cell plasmalemmal vesicles, nor was there a significant variation of these structures among individuals. Numbers of dermal microfibril bundles diminished with age (p less than 0.01). Anchoring fibril counts varied widely both among individuals (p less than 0.025) and within the same subject; there were fewer in the upper arm compared with different parts of the leg (p less than 0.005). These results emphasize the importance of appropriate controls in studies of physiologic and pathologic conditions involving the dermal-epidermal junction.

Evaluation of anchoring fibrils and other components of the dermal-epidermal junction in dystrophic epidermolysis bullosa by a quantitative ultrastructural technique.

To examine the possibility that differences in the structure and population density of anchoring fibrils (AF) and other components of the dermal-epidermal junction might distinguish between genetically and clinically distinct varieties of dystrophic epidermolysis bullosa (DEB), a controlled ultrastructural morphometric study of nonseparated keratinocyte-associated dermal-epidermal junction was undertaken in a total of 17 patients with DEB. Seven patients had dominant DEB, 3 had localized recessive DEB, and 7 had severe, generalized recessive DEB. Nonlesional, unscarred skin was obtained from standard body regions. Criteria for the identification of AF were a mandatory union with the lamina densa and the presence of central banding and/or fanning of the extremities. No AF were detected in 9 technically suitable samples from patients with severe recessive DEB. Structurally normal AF were present, but significantly reduced in number, in both dominant and localized recessive DEB, compared with site-matched samples from 12 healthy adults. There was no difference in AF characteristics between dominant and localized recessive DEB, or between sites of predilection and nonpredilection for blisters. The presence or absence of albopapuloid lesions in dominant DEB did not influence AF counts. There was no difference in numbers of hemidesmosomes, basal cell plasmalemmal vesicles, or dermal microfibril bundles in any group of DEB patients compared with controls. Thus, although severe mutilating DEB can be distinguished by routine transmission electron microscopy, the dominant and localized recessive forms cannot be differentiated on the basis of AF structure or numbers.

Major histocompatibility class II antigen expression on the surface of epidermal cells from normal and ultraviolet B irradiated subjects.

The influence of ultraviolet B irradiation in therapeutic doses on MHC II-positive epidermal cell numbers and their surface MHC II antigen expression was studied quantitatively using light microscopic immunoperoxidase and immunogold electron microscopic techniques. In multiple ultrathin sections through many MHC II-positive epidermal cells from five healthy subjects, prior to ultraviolet exposure, Langerhans cells and indeterminate cells were found to express similar densities of surface MHC II antigens, which were uniformly distributed over the cell surface. The variation in surface MHC II antigen expression on 97 dendritic epidermal cells from one subject was normally distributed. Following a 6-week course of ultraviolet B irradiation, in the same doses as those normally used for the treatment of psoriasis, MHC II-positive epidermal cell numbers were significantly reduced (mean decrease to 51% of the pre-UVB sample; p < 0.001 analysis of variance), but their surface MHC class II antigen density was significantly increased (p < 0.05 analysis of variance). No MHC II-negative Langerhans cells were detected in either the pre- or post-UVB samples.

Severe palmo-plantar hyperkeratosis in Dowling-Meara epidermolysis bullosa simplex caused by a mutation in the keratin 14 gene (KRT14).

Mutant keratins 5 or 14 are implicated in the etiology of epidermolysis bullosa simplex (EBS). The catalog of mutations has established certain patterns of mutation clusters from which it may be possible, along with associated biochemical data, to predict phenotypic severity. It is becoming apparent that some of these assumptions may now require modification. We report a mutation in the gene encoding keratin 14 (KRT14) that changes the predicted amino acid at position 119, at the start of the helix initiation motif, from methionine to threonine (K14 M119T) in a patient with an EBS Dowling-Meara phenotype with severe palmo-plantar hyperkeratosis. This demonstrates that the three major types of EBS can arise from missense mutations in the same codon. The findings suggest that the specific nature of the missense mutation, in the context of the protein sequence, can contribute far more to the clinical severity than previously thought. The different EBS subtypes should be viewed as gradations of clinical severity rather than distinct genetic diseases.

Hemidesmosomes show abnormal association with the keratin filament network in junctional forms of epidermolysis bullosa.

Junctional epidermolysis bullosa is a group of hereditary bullous disorders resulting from defects in several hemidesmosome-anchoring filament components. Because hemidesmosomes are involved not only in keratinocyte-extracellular matrix adherence, but also in normal anchorage of keratin intermediate filaments to the basal keratinocyte membrane, we questioned whether this intracellular function of hemidesmosomes was also perturbed in junctional epidermolysis bullosa. We used quantitative electron microscopic methods to assess certain morphologic features of hemidesmosome-keratin intermediate filaments interactions in skin from normal subjects (n = 11) and from patients with different forms of junctional epidermolysis bullosa (n = 13). In addition, skin from patients with autosomal recessive epidermolysis bullosa simplex with plectin defects (n = 3) or with autosomal recessive dystrophic epidermolysis bullosa (n = 4) were included as controls. Values were expressed as a percentage of the total number of hemidesmosomes counted. In normal skin 83.3% +/- 3.3 (SEM) hemidesmosomes were associated with keratin intermediate filaments and 90.1% +/- 1.9 had inner plaques. In Herlitz junctional epidermolysis bullosa (laminin 5 abnormalities, n = 4) these values were reduced to 45.3% +/- 11.5 (p < 0.001; analysis of variance) and 50.3% +/- 12.8 (p < 0.001), respectively. In junctional epidermolysis bullosa with pyloric atresia (alpha6beta4 abnormalities, n = 3) the values were also reduced [41.8% +/- 7.0 (p < 0.001) and 44.5% +/- 5.7 (p < 0.001), respectively]. In the non-Herlitz group (laminin 5 mutations, n = 3) the counts were 66.7% +/- 7.1 (p > 0.05) and 70.5% +/- 8.5 (p < 0.05), and in skin from patients with bullous pemphigoid antigen 2 mutations (n = 3) the counts were 54.3% +/- 13.8 (p < 0.01) and 57.1% +/- 13.9 (p < 0.01). In epidermolysis bullosa simplex associated with plectin mutations the values were 31.9% +/- 8.9 (p < 0.001) for keratin intermediate filaments association and 39.9% +/- 7.1 (p < 0.001) for inner plaques. Findings in recessive dystrophic epidermolysis bullosa patients' skin were indistinguishable from normal control skin with inner plaques (90.5% +/- 2.5) and keratin intermediate filaments attachment (86.3% +/- 2.1). These findings suggest that the molecular abnormalities underlying different forms of junctional epidermolysis bullosa appear to affect certain critical intracellular functions of hemidesmosomes, such as the normal connections with keratin intermediate filaments. This may have important implications for the maintenance of basal keratinocyte integrity and resilience in junctional epidermolysis bullosa.

Missense mutations in keratin 17 cause either pachyonychia congenita type 2 or a phenotype resembling steatocystoma multiplex.

Pachyonychia congenita (PC) is a group of autosomal dominant ectodermal dysplasias in which the main phenotypic characteristic is hypertrophic nail dystrophy. In the Jackson-Lawler form (PC-2), pachyonychia is accompanied by multiple pilosebaceous cysts, natal teeth, and hair abnormalities. By direct sequencing of genomic PCR products, we report heterozygous K17 missense mutations in the same conserved protein motif in a further five PC-2 families (K17 N92S in one familial and three sporadic cases; K17 Y98D in one familial case) confirming that mutations in this gene are a common cause of PC-2. We also show heterozygous missense mutations in K17 (N92H and R94H) in two families diagnosed as steatocystoma multiplex. Mild nail defects were observed in some but not all of these patients on clinical re-evaluation of these families. All the K17 mutations reported here were shown to co-segregate with the disease in the pedigrees analyzed and were excluded from 100 unaffected, unrelated chromosomes by restriction enzyme analysis of K17 genomic PCR products. We conclude that phenotypic variation is observed with K17 mutations, as is the case with other keratin disorders.

Rapid processing of fetal skin for prenatal diagnosis by light and electron microscopy.

A method has been developed for rapid processing of fetal skin for prenatal diagnosis of hereditary skin diseases by light and electron microscopy. Fixation, dehydration, embedding, and polymerisation can be achieved in about 5 h. The quality of tissue preservation compares favourably with that produced by slower conventional techniques. This procedure may provoke a wider interest in the potential use of fetal skin biopsy in prenatal diagnosis, especially if identification of structural abnormalities is a feasible alternative to more time consuming biochemical analysis.

Structural and functional properties of the dermoepidermal junction in obligate heterozygotes for recessive forms of epidermolysis bullosa.

To determine whether heterozygotes for the severe recessive forms of epidermolysis bullosa (EB) partially express characteristic structural or functional abnormalities of the dermoepidermal junction, and thereby allow detection of the carrier state, a controlled morphometric analysis of the junction and the measurement of suction blister times were undertaken in obligate heterozygotes for junctional EB and generalized-recessive dystrophic EB. Skin from generalized recessive dystrophic EB carriers had significantly reduced numbers of anchoring fibrils, and suction blisters showed a tendency to form more rapidly in junctional EB carriers. However, neither of these abnormalities is sufficiently large or consistent to enable the reliable identification of the respective heterozygote state.