Dermoscopy for melanoma detection and triage in primary care: a systematic review

OBJECTIVE

Most skin lesions first present in primary care, where distinguishing rare melanomas from benign lesions can be challenging. Dermoscopy improves diagnostic accuracy among specialists and is promoted for use by primary care physicians (PCPs). However, when used by untrained clinicians, accuracy may be no better than visual inspection. This study aimed to undertake a systematic review of literature reporting use of dermoscopy to triage suspicious skin lesions in primary care settings, and challenges for implementation.

DESIGN

A systematic literature review and narrative synthesis.

DATA SOURCES

We searched MEDLINE, Cochrane Central, EMBASE, Cumulative Index to Nursing and Allied Health Literature, and SCOPUS bibliographic databases from 1 January 1990 to 31 December 2017, without language restrictions.

INCLUSION CRITERIA

Studies including assessment of dermoscopy accuracy, acceptability to patients and PCPs, training requirements, and cost-effectiveness of dermoscopy modes in primary care, including trials, diagnostic accuracy and acceptability studies.

RESULTS

23 studies met the review criteria, representing 49 769 lesions and 3708 PCPs, all from high-income countries. There was a paucity of studies set truly in primary care and the outcomes measured were diverse. The heterogeneity therefore made meta-analysis unfeasible; the data were synthesised through narrative review. Dermoscopy, with appropriate training, was associated with improved diagnostic accuracy for melanoma and benign lesions, and reduced unnecessary excisions and referrals. Teledermoscopy-based referral systems improved triage accuracy. Only three studies examined cost-effectiveness; hence, there was insufficient evidence to draw conclusions. Costs, training and time requirements were considered important implementation barriers. Patient satisfaction was seldom assessed. Computer-aided dermoscopy and other technological advances have not yet been tested in primary care.

CONCLUSIONS

Dermoscopy could help PCPs triage suspicious lesions for biopsy, urgent referral or reassurance. However, it will be important to establish further evidence on minimum training requirements to reach competence, as well as the cost-effectiveness and patient acceptability of implementing dermoscopy in primary care.

TRIAL REGISTRATION NUMBER

CRD42018091395.

ANCA Associated with Behçet's Disease

Behçcet's disease is a multisystem disorder affecting primarily mucocutaneous and ocular sites although the gastrointestinal, cardiovascular, central nervous and respiratory systems may also be involved. Hulusi Behçet, a Turkish dermatologist, first described Behçet's disease in 1937 and suggested a possible infectious aetiology1. The pathogenesis of this condition still remains unclear although it is likely that infection acts as a trigger in genetically susceptible individuals.

We report a patient with unusual cutaneous manifestations of Behçet's disease and antineutrophil cytoplasmic antibodies (ANCA) directed against the cytotoxic protein, bactericidal/permeability-increasing protein (BPI). This is the first report of Behçet's disease associated with this autoantibody.

Mutations in AEC syndrome skin reveal a role for p63 in basement membrane adhesion, skin barrier integrity and hair follicle biology

BACKGROUND

AEC (ankyloblepharon-ectodermal defects-clefting) syndrome is an autosomal dominant ectodermal dysplasia disorder caused by mutations in the transcription factor p63. Clinically, the skin is dry and often fragile; other features can include partial eyelid fusion (ankyloblepharon), hypodontia, orofacial clefting, sparse hair or alopecia, and nail dystrophy.

OBJECTIVES

To investigate how p63 gene mutations affect gene and protein expression in AEC syndrome skin.

METHODS

We performed microarray analysis on samples of intact and eroded AEC syndrome skin compared with control skin. Changes were verified by quantitative real-time reverse transcription-polymerase chain reaction and, for basal keratinocyte-associated genes, by immunohistochemistry and analysis of microdissected skin.

RESULTS

We identified significant upregulation of six genes and downregulation of 69 genes in AEC syndrome skin, with the main changes in genes implicated in epidermal adhesion, skin barrier formation and hair follicle biology. There was reduced expression of genes encoding the basement membrane proteins FRAS1 and collagen VII, as well as the skin barrier-associated small proline-rich proteins 1A and 4, late cornified envelope protein 5A, hornerin, and lipid transporters including ALOX15B. Reduced expression of the hair-associated keratins 25, 27, 31, 33B, 34, 35, 81 and 85 was also noted. We also confirmed similar alterations in gene expression for 26 of the 75 genes in eroded AEC scalp skin.

CONCLUSIONS

This study identifies specific changes in skin structural biology and signalling pathways that result from mutant p63 and provides new molecular insight into the AEC syndrome phenotype.

Pseudoepitheliomatous, keratotic and micaceous balanitis after penile squamous cell carcinoma

Pseudoepitheliomatous keratotic and micaceous balanitis (PKMB) is a rare form of balanitis, with only a handful of cases reported since the disease was first described. Although the condition has been described as benign, there is increasing evidence of its premalignant potential, with several of the reported cases progressing to verrucous or squamous cell carcinoma (SCC). We report a case of PKMB following penile SCC and discuss the literature on this rare condition.

Multiple primary malignancies in patients with Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is a rare malignant cutaneous tumour, the incidence of which is increasing. Second malignancies have been reported to occur with high incidence in these patients.

OBJECTIVES

We report the rate and nature of multiple malignancies in patients with MCC treated over a 10 year period in Addenbrooke's Hospital in Cambridge, United Kingdom, as well as the temporal relationship of these additional malignancies to the diagnosis of MCC.

RESULTS

The 27 patients had an approximately equal sex incidence with a median age at diagnosis of 79 years. Seventy percent (n=19) of patients had a second primary malignant tumour; and 7 of these patients had two or more tumours in addition to the MCC. Eighteen patients had additional cutaneous malignancies: melanoma, squamous cell carcinoma and basal cell carcinoma, and 8 patients presented non-cutaneous malignancy including colorectal, haematological and breast tumours. Of the 28 additional tumours in our patients, half were diagnosed prior to presentation of MCC, 32% within 6 months of diagnosis, and 18% between 6 months and 3 years after diagnosis. Possible reasons for the high rate of additional tumours in this population are discussed.

CONCLUSIONS

Our figures reflect a higher incidence of multiple malignancies in those with Merkel cell tumour than has previously been reported. This has important implications for the care and surveillance of these patients.

Short‐term growth and bone turnover in children undergoing occlusive steroid (‘Wet‐Wrap’) dressings for treatment of atopic eczema

To assess the effects of steroid wet-wrap therapy on short-term growth and bone turnover, eight prepubertal (M:F,5:3) children with a median age of 5.1years (range 3.3-8.8) were studied over a 2-week period prior to therapy and at 2-week intervals during therapy. Short-term growth was assessed by measuring lower leg length velocity (LLLV) by knemometry and bone and collagen turnover was assessed by urinary deoxypyridinoline crosslink excretion corrected for creatinine excretion (DPD). Median duration of study during occlusive dressings was 12 weeks (range 2-18). Topical beclomethasone dipropionate diluted 1:10 or 1:4 in white soft paraffin was applied under tubular (Tubifast) bandages in 7/8 children. Median LLLV before and during therapy were 0.43 mm/week (10(th),90(th) centile; 0.0,0.7) and 0.42 mm/week (10(th),90(th) centile; -0.35,1.01), respectively (not significant). Median DPD before and during therapy were 25.9 nmol/l/creatinine (10(th),90(th) centile; 20.8, 33.0) and 26.3 nmol/l/creatinine (10(th),90(th) centile; 21.7, 34.1) respectively (not significant). Non-invasive assessment of the effects of steroid wet-wrap therapy can be performed in children with eczema. These preliminary results show no substantial growth promoting or adverse effects of therapy.

Smoking related COPD and facial wrinkling: is there a common susceptibility?

BACKGROUND

Cigarette smoking causes accelerated facial wrinkling and predisposes to chronic obstructive pulmonary disease (COPD). However, it has long been recognised that there is a subgroup of susceptible smokers who are at increased risk of developing airflow obstruction. We have tested the hypothesis that there is a common susceptibility for the development of COPD and facial wrinkling in cigarette smokers.

METHODS

One hundred and forty nine current and ex-smokers were recruited from a family based study of COPD genetics, 68 (45.6%) of whom fulfilled the definition of COPD. 124 (83.2%) had no or minor facial wrinkling (Daniell <IV) and 25 (16.8%) were wrinkled (Daniell score >/=IV). Generalised estimating equations were used to adjust for familial correlations between related individuals and the potential confounding effects of age and pack years smoked.

RESULTS

Forced expiratory volume in 1 second (FEV(1)) was significantly lower in those with wrinkles than in those without (mean difference in FEV(1) % predicted -13.7%, 95% CI -27.5 to 0.0, p = 0.05) and facial wrinkling was associated with a substantially increased risk of COPD (adjusted OR 5.0, 95% CI 1.3 to 18.5, p<0.02). The Daniell score correlated with the extent of emphysema on the CT scan (p<0.05) and facial wrinkling was also associated with a greater risk of more extensive emphysema (adjusted OR 3.0, 95% CI 1.0 to 9.3, p = 0.05).

CONCLUSION

Facial wrinkling is associated with COPD in smokers, and both disease processes may share a common susceptibility. Facial wrinkling in smokers may therefore be a biomarker of susceptibility to COPD.

Transient bullous dermolysis of the newborn in three generations

Transient bullous dermolysis of the newborn (TBDN) is a rare form of dystrophic epidermolysis bullosa (DEB) that presents with neonatal skin blistering but which usually improves markedly during early life or even remits completely. Skin biopsies reveal abnormal intraepidermal accumulation of type VII collagen which results in poorly constructed anchoring fibrils and a sublamina densa plane of blister formation. The reason for the spontaneous clinical improvement is not known, but there is a gradual recovery in type VII collagen secretion from basal keratinocytes to the dermal-epidermal junction, with subsequent improvement or correction of anchoring fibril morphology. In this report, we describe TBDN occurring in three generations of the same family. Blistering occurred only during the first few months after birth, and all affected individuals were found to have a heterozygous glycine substitution mutation in exon 45 of the type VII collagen gene, COL7A1, designated G1522E. This mutation represents the third report of a pathogenic COL7A1 mutation in TBDN. Despite limited understanding of the disease mechanism in TBDN, this distinct form of DEB is important to recognize as it typically has a benign and self-limiting course. However, not all cases of DEB associated with intraepidermal type VII collagen are 'transient'. Genetic counselling in such patients therefore should be guarded until the pathophysiology of TBDN is better understood.

Genetic and functional analyses of FH mutations in multiple cutaneous and uterine leiomyomatosis, hereditary leiomyomatosis and renal cancer, and fumarate hydratase deficiency

Germline mutations of the fumarate hydratase (FH, fumarase) gene are found in the recessive FH deficiency syndrome and in dominantly inherited susceptibility to multiple cutaneous and uterine leiomyomatosis (MCUL). We have previously reported a number of germline FH mutations from MCUL patients. In this study, we report additional FH mutations in MCUL and FH deficiency patients. Mutations can readily be found in about 75% of MCUL cases and most cases of FH deficiency. Some of the more common FH mutations are probably derived from founding individuals. Protein-truncating FH mutations are functionally null alleles. Disease-associated missense FH changes map to highly conserved residues, mostly in or around the enzyme's active site or activation site; we predict that these mutations severely compromise enzyme function. The mutation spectra in FH deficiency and MCUL are similar, although in the latter mutations tend to occur earlier in the gene and, perhaps, are more likely to result in a truncated or absent protein. We have found that not all mutation-carrier parents of FH deficiency children have a strong predisposition to leiomyomata. We have confirmed that renal carcinoma is sometimes part of MCUL, as part of the variant hereditary leiomyomatosis and renal cancer (HLRCC) syndrome, and have shown that these cancers may have either type II papillary or collecting duct morphology. We have found no association between the type or site of FH mutation and any aspect of the MCUL phenotype. Biochemical assay for reduced FH functional activity in the germline of MCUL patients can indicate carriers of FH mutations with high sensitivity and specificity, and can detect reduced FH activity in some patients without detectable FH mutations. We conclude that MCUL is probably a genetically homogeneous tumour predisposition syndrome, primarily resulting from absent or severely reduced fumarase activity, with currently unknown functional consequences for the smooth muscle or kidney cell.

Dissecting folliculitis of the scalp with marginal keratitis

We describe a young man with dissecting folliculitis of the scalp, who subsequently developed marginal keratitis. We are unaware of any previous reports of this association. The aetiology of dissecting folliculitis is thought to relate to abnormal follicular occlusion with subsequent suppuration, although an infective process has never been established. Marginal keratitis is postulated, but not proven, to be caused by an enhanced immune response to Staphylococcus aureus antigens. We suggest that a similar abnormal response to infection may be important in these two conditions. This case also highlights ocular complications which may occur in patients with dissecting folliculitis.

Elastosis perforans serpiginosa and associated disorders

We report elastosis perforans serpiginosa (EPS) arising in three patients with Ehlers-Danlos syndrome, osteogenesis imperfecta and Down's syndrome. These cases illustrate some of the rare but well-recognized disease associations with EPS. The other causes of EPS are reviewed.

Dispersal of radioisotope labelled solution following deep dermal injection in Ehlers-Danlos syndrome

Ehlers-Danlos syndrome (EDS) is the commonest inherited disorder of connective tissue, affecting around 10 000 patients in the UK. Patients with EDS have reported that local anaesthetic is often ineffective. Patients with less severe skin laxity often have the most problems. We have postulated that this resistance to local anaesthetics is not due to the lax connective tissues as is often assumed. This study used radioactively labelled solution ((99m)Tc-pertechnetate) administered as a deep dermal injection in the forearm. The rate of dispersal of isotope was measured over 60 min and found to be identical between six patients with EDS and three controls. The effects of local anaesthetics are complex and depend on the individual chemical properties of the agent and a number of tissue factors. This study would suggest that the lack of effectiveness of local anaesthetic solutions is not due to rapid dispersal of solution. It is unlikely therefore that its lack of effect can be compensated for by simply increasing the amount used. The diagnosis of EDS should be considered in any patient who complains unexpectedly of pain during their procedure, particularly when the surgeon knows that an adequate volume of local anaesthetic has been used.

The molecular genetics of the Ehlers-Danlos syndrome

The identification and investigation of many inherited disorders has an importance out of proportion to their frequency because of the insights they provide into physiological, pathological and molecular mechanisms. This is true of the heritable disorders of connective tissue which are a diverse group of conditions involving cutaneous, musculoskeletal, cardiovascular, ocular, gastrointestinal and pulmonary systems. The Ehlers-Danlos syndrome (EDS), which shows great clinical variability and genetic heterogeneity, is one example which has particular relevance to the dermatologist and is the focus of this review.

A single base mutation in COL5A2 causes Ehlers-Danlos syndrome type II

Ehlers-Danlos syndrome (EDS) is a heterogeneous group of connective tissue disorders. Recently mutations have been found in the genes for type V collagen in a small number of people with the most common forms of EDS, types I and II. Here we characterise a COL5A2 mutation in an EDS II family. Cultured dermal fibroblasts obtained from an affected subject synthesised abnormal type V collagen. Haplotype analysis excluded COL5A1 but was concordant with COL5A2 as the disease locus. The entire open reading frame of the COL5A2 cDNA was directly sequenced and a single base mutation detected. It substituted a glycine residue within the triple helical domain (G934R) of alpha2(V) collagen, typical of the dominant negative changes in other collagens, which cause various other inherited connective tissue disorders. All three affected family members possessed the single base change, which was absent in 50 normal chromosomes.

A point mutation in an intronic branch site results in aberrant splicing of COL5A1 and in Ehlers-Danlos syndrome type II in two British families

Ehlers-Danlos syndrome (EDS) is a heterogeneous group of connective-tissue disorders characterized by skin fragility, joint laxity, and skeletal deformities. Type V collagen appears to have a causal role in EDS types I and II, which show phenotypic overlap and may sometimes be allelic. Type V collagen can exist as a heterotrimer, [alpha1(V)]2alpha2(V), and it both coassembles with and regulates type I collagen-fibril diameter. Using an intragenic COL5A1 polymorphism, we have demonstrated linkage, at zero recombination, to the same allele in two large British EDS type II families (LOD scores 4.1 and 4.3). Affected members from each family were heterozygous for a point mutation in intron 32 (IVS32:T-25G), causing the 45-bp exon 33 to be lost from the mRNA in approximately 60% of transcripts from the mutant gene. This mutation lies only 2 bp upstream of a highly conserved adenosine in the consensus branch-site sequence, which is required for lariat formation. Although both families shared the same marker allele, we have been unable to identify a common genealogy. This is the first description of a mutation at the lariat branch site, which plays a pivotal role in the splicing mechanism, in a collagen gene. Very probably, the resulting in-frame exon skip has a dominant-negative effect due to incorporation of the mutant proalpha chain into the triple-helical molecule. These findings further confirm the importance of type V collagen in the causation of EDS type II, and the novel collagen mutation indicates the importance of the lariat branch site in splicing.

Giant bladder diverticulum in Ehlers-Danlos syndrome type I causing outflow obstruction

We describe a 16-year-old patient with Ehlers-Danlos syndrome (EDS) type I and recurrent urinary retention caused by giant bladder diverticulum and review the literature on this association.