There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Over the last few years, dermoscopy has been shown to be a useful tool in assisting the noninvasive diagnosis of various general dermatological disorders. In this article, we sought to provide an up-to-date practical overview on the use of dermoscopy in general dermatology by analysing the dermoscopic differential diagnosis of relatively common dermatological disorders grouped according to their clinical presentation, i.e. dermatoses presenting with erythematous-desquamative patches/plaques (plaque psoriasis, eczematous dermatitis, pityriasis rosea, mycosis fungoides and subacute cutaneous lupus erythematosus), papulosquamous/papulokeratotic dermatoses (lichen planus, pityriasis rosea, papulosquamous sarcoidosis, guttate psoriasis, pityriasis lichenoides chronica, classical pityriasis rubra pilaris, porokeratosis, lymphomatoid papulosis, papulosquamous chronic GVHD, parakeratosis variegata, Grover disease, Darier disease and BRAF-inhibitor-induced acantholytic dyskeratosis), facial inflammatory skin diseases (rosacea, seborrheic dermatitis, discoid lupus erythematosus, sarcoidosis, cutaneous leishmaniasis, lupus vulgaris, granuloma faciale and demodicidosis), acquired keratodermas (chronic hand eczema, palmar psoriasis, keratoderma due to mycosis fungoides, keratoderma resulting from pityriasis rubra pilaris, tinea manuum, palmar lichen planus and aquagenic palmar keratoderma), sclero-atrophic dermatoses (necrobiosis lipoidica, morphea and cutaneous lichen sclerosus), hypopigmented macular diseases (extragenital guttate lichen sclerosus, achromic pityriasis versicolor, guttate vitiligo, idiopathic guttate hypomelanosis, progressive macular hypomelanosis and postinflammatory hypopigmentations), hyperpigmented maculopapular diseases (pityriasis versicolor, lichen planus pigmentosus, Gougerot-Carteaud syndrome, Dowling-Degos disease, erythema ab igne, macular amyloidosis, lichen amyloidosus, friction melanosis, terra firma-forme dermatosis, urticaria pigmentosa and telangiectasia macularis eruptiva perstans), itchy papulonodular dermatoses (hypertrophic lichen planus, prurigo nodularis, nodular scabies and acquired perforating dermatosis), erythrodermas (due to psoriasis, atopic dermatitis, mycosis fungoides, pityriasis rubra pilaris and scabies), noninfectious balanitis (Zoon’s plasma cell balanitis, psoriatic balanitis, seborrheic dermatitis and non-specific balanitis) and erythroplasia of Queyrat, inflammatory cicatricial alopecias (scalp discoid lupus erythematosus, lichen planopilaris, frontal fibrosing alopecia and folliculitis decalvans), nonscarring alopecias (alopecia areata, trichotillomania, androgenetic alopecia and telogen effluvium) and scaling disorders of the scalp (tinea capitis, scalp psoriasis, seborrheic dermatitis and pityriasis amiantacea).

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Dermoscopy in General Dermatology: A Practical Overview

Non-melanoma skin cancer represents one-third of all malignancies and its incidence is expected to rise until the year 2040. Cutaneous squamous cell carcinoma (cSCC) represents 20 % of all non-melanoma skin cancer and is a deadly threat owing to its ability to metastasize to any organ in the body. Therefore, a better understanding of cSCC is essential to strengthen preventative measures and curable treatment options. Currently, research demonstrates that cSCC is diagnosed at a rate of 15–35 per 100,000 people and is expected to increase 2–4 % per year. With respect to metastatic cSCC, this disease is more common in men; people over the age of 75 years; and inhabitants of the south and mid-west USA. In 2010, the American Joint Committee on Cancer updated the Cancer Staging Manual’s primary tumor designation to now include high-risk factors; however, factors such as immunosuppression and tumor recurrence were not included. Other staging systems such as Brigham and Women’s Hospital have allowed for increased stratification of cSCC. High-risk cSCC is defined as a cSCC that is staged as N0, extends beyond basement membrane, and has high-risk features associated with sub-clinical metastasis. High-risk features are depth of invasion (>2 mm), poor histological differentiation, high-risk anatomic location (face, ear, pre/post auricular, genitalia, hands, and feet), perineural involvement, recurrence, multiple cSCC tumors, and immunosuppression. Epidermal growth factor receptor and nuclear active IκB kinase (IKK) expression are also predictive of metastatic capabilities. Clinically, the initial lesions of a cSCC tumor can present as a painless plaque-like or verrucous tumor that can ultimately progress to being large, necrotic, and infected. Tumors can also present with paresthesias or lymphadenopathy depending on the location involved. With respect to prognosis, metastatic cSCC is lethal, with several large studies demonstrating a mortality rate of >70 %. Therefore, treatment of metastatic cSCC is difficult and depends on the location involved and extent of metastasis. Treatment options include surgery, radiation therapy, chemotherapy, and any combination of the above. Surgery alone can be used for metastatic cSCC treatment, but is not as effective as surgery in conjunction with radiation therapy. Radiation therapy has some success as a monotherapy in low-risk or cosmetically sensitive areas such as the external ear, eyelid or nose. According to the 2013 National Comprehensive Cancer Network Guidelines, cisplatin as a single agent or combined with 5-fluorouracil hold the strongest support for the treatment of metastatic cSCC; however, the supporting evidence is inconsistent and a curative chemotherapeutic approach is still lacking. Epidermal growth factor receptor inhibitors are a newer class of agents being used in metastatic cSCC and hold some promise as a therapy for this disease. Other areas of interest in finding curative treatments for metastatic cSCC include p53, hypermethylation of specific genes, chromatin remodeling genes, and the RAS/RTK/PI3K pathway. This review addresses the epidemiology, staging, risk factors, clinical presentation, management, and new trends in the treatment of high-risk and metastatic cSCC.

Cutaneous Squamous Cell Carcinoma: A Review of High-Risk and Metastatic Disease

Sarcoidosis is a common systemic, noncaseating granulomatous disease of unknown etiology. The development of sarcoidosis has been associated with a number of environmental factors and genes. Cutaneous sarcoidosis, the "great imitator," can baffle clinicians because of its diverse manifestations and its ability to resemble both common and rare cutaneous diseases. Depending on the type, location, and distribution of the lesions, treatment can prevent functional impairment, symptomatic distress, scarring, and disfigurement. Numerous therapeutic options are available for the treatment of cutaneous sarcoidosis, but there are few well designed trials to guide practitioners on evidence-based, best practice management. In part I, we review the current knowledge and advances in the epidemiology, etiology, pathogenesis, and genetics of sarcoidosis, discuss the heterogeneous manifestations of cutaneous sarcoidosis, and provide a guide for treatment of cutaneous sarcoidosis.

https://www.jaad.org/article/S0190-9622(12)00112-0/pdf

Sarcoidosis: A comprehensive review and update for the dermatologist: Part I. Cutaneous disease

Levamisole is a pharmaceutical with anthelminthic and immunomodulatory properties that was previously used in both animals and humans to treat inflammatory conditions and cancer. Levamisole has been identified as a cocaine adulterant in the United States since 2003. By 2009, the United States Drug Enforcement Administration (DEA) estimated that 69% of the cocaine seized contained levamisole. The first case reports of complications related to levamisole in cocaine users were published in 2009. The objectives of this article are to review the literature regarding the full spectrum of possible complications related to levamisole use for medical purposes, to review the current scope of levamisole-induced complications in cocaine users and to discuss the pharmacological properties that might explain the motivation behind the large-scale adulteration of cocaine with levamisole. Literature review revealed that significant complications were quickly reported when levamisole was used in inflammatory conditions. By 1976, several cases of leukopenia and agranulocytosis were reported. Recurrence with re-exposure was well described and agranulocytosis spontaneously reversed upon discontinuation of therapy. Vasculitis secondary to levamisole treatment was first reported in 1978 and mostly manifests as leukocytoclastic vasculitis, cutaneous necrotising vasculitis and thrombotic vasculopathy without vasculitis. These findings typically, but not invariably, involve the ear lobes. Discontinuation of levamisole therapy was again a critical part of the treatment. Various neurological side effects were described with levamisole therapy, the most concerning complication being multifocal inflammatory leukoencephalopathy (MIL). Literature review identified 203 unique cases of complications in cocaine users that can be attributed to levamisole adulteration. The two principal complications reported are haematological (140 cases of neutropenia) and dermatological (84 cases). Even though these complications can occur in isolation, many cases displayed both simultaneously. No formal case of leukoencephalopathy in the setting of cocaine use has been reported so far. A striking phenomenon is the apparent high level of recurrence (27.1%) of symptoms in cocaine users after re-exposure to cocaine that is presumably adulterated. The importance of accurately identifying levamisole-induced complications is therefore critical for symptomatic patients as discontinuation of exposure is fundamental and as a correct diagnosis prevents unnecessary and potentially dangerous use of other treatment modalities like powerful immunosuppressive therapy. Literature review suggests that levamisole might have the advantages of enhancing noradrenergic neurotransmission by inhibiting reuptake, by inhibiting MAO and/or COMT, by acting on ganglionic nicotinic receptors and by being partially metabolized into an amphetamine-like compound. It could also increase endogenous opioids and increase dopamine concentration in the cerebral reward pathway. These potential effects make levamisole an interesting choice as a cocaine adulterant. It seems unlikely that levamisole use as a cocaine adulterant will soon reach an end. More information is needed about the diagnosis and treatment of levamisole-induced complications, and the efforts of the medical and public health community is needed to face this challenging problem.

Levamisole in cocaine: Unexpected news from an old acquaintance

Nonmelanoma skin cancer (NMSC) is the most common form of cancer in the Caucasian population, with squamous cell carcinoma (SCC) accounting for the majority of NMSC-related metastases and death While most SCC lesions are indolent tumors with low malignant potential, a wide diversity of SCC subtypes exist, several of which are associated with markedly more aggressive behaviors Distinguishing these high-risk variants from their counterparts is possible through microscopic analysis, since each subtype possesses unique histopathological features Early identification of high-risk lesions can allow for more rapid therapeutic intervention, reducing the likelihood of metastasis and death The authors review specific histopathological features and associated clinical outcomes of the primary subdivisions of SCC

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Histopathological Variants of Cutaneous Squamous Cell Carcinoma: A Review

We report a 50-year-old woman who presented with a six-month history of recurrent retiform purpura of uncertain etiology. Laboratory findings included neutropenia, positive anticardiolipin IgM antibody, and a weakly positive p-ANCA. Histopathology revealed a leukocytoclastic vasculitis with intravascular thrombi. Urine toxicology screen was positive for cocaine. These findings are similar to recent reports of agranulocytosis and purpura induced by levamisole-tainted cocaine. A review of the clinical and histopathological findings associated with levamisole-induced purpura will be discussed.

Retiform purpura: A new stigmata of illicit drug use? - eScholarship

As reflected in the literature, the use of dermal filler agents has increased substantially over the last decade. Consequently, these agents are more frequently encountered on histopathologic examination. A variety of dermal fillers can be readily identified histopathologically, and the accurate identification of these agents is a critical task for dermatopathologists. Furthermore, a basic understanding of the histological features of fillers has relevance to dermatologists and dermatologic surgeons. The identification of filler substances may have important diagnostic, medico-legal and medical management considerations. This concise review aims to provide a pragmatic approach to distinguishing the agents most frequently encountered in routine practice and in the literature.

Histopathologic identification of dermal filler agents.

Acquired Perforating Dermatosis (APD) is a perforating disease characterized by transepidermal elimination of dermal material [1,2]. This disease usually develops in adulthood. APD has been reported to occur in association with various diseases, but is most commonly associated with dialysis-dependent chronic renal failure (CRF) or diabetes mellitus (DM) [1,2,3,4]. Morton et al found that APD occurs in up to 10% of patients undergoing hemodialysis [5]. Additionally, Saray et al found that sixteen of twenty-two cases with APD were associated with CRF [3].

/pdf/acquired-perforating-dermatosis-a-clinical-and-dermatoscopic-35x698lv6u.pdf

Stephen E. Mercer

Papers

Histopathological Variants of Cutaneous Squamous Cell Carcinoma: A Review

Retiform purpura: A new stigmata of illicit drug use? - eScholarship

Histopathologic identification of dermal filler agents.

Acquired perforating dermatosis: a clinical and dermatoscopic correlation.

Retiform purpura: a new stigmata of illicit drug use?