Cutaneous manifestations of familial amyloidotic polyneuropathy

Seborrheic Dermatitis and Dandruff: A Comprehensive Review

Seborrheic Dermatitis (SD) and dandruff are of a continuous spectrum of the same disease that affects the seborrheic areas of the body. Dandruff is restricted to the scalp, and involves itchy, flaking skin without visible inflammation. SD can affect the scalp as well as other seborrheic areas, and involves itchy and flaking or scaling skin, inflammation and pruritus. Various intrinsic and environmental factors, such as sebaceous secretions, skin surface fungal colonization, individual susceptibility, and interactions between these factors, all contribute to the pathogenesis of SD and dandruff. In this review, we summarize the current knowledge on SD and dandruff, including epidemiology, burden of disease, clinical presentations and diagnosis, treatment, genetic studies in humans and animal models, and predisposing factors. Genetic and biochemical studies and investigations in animal models provide further insight on the pathophysiology and strategies for better treatment.

Abnormalities of Skin and Cutaneous Appendages in Neuromuscular Disorders

OBJECTIVES

A thorough evaluation of the skin and its appendages is frequently outside the area of expertise of the neurologist who deals with neuromuscular disorders. However, the skin is more frequently affected in neuromuscular disorders and deserves more attention than so far acknowledged.

METHODS

Review of publications by searching Medline dealing with skin disorders in neuromuscular disorders.

RESULTS

Skin abnormalities are most frequently found in patients with dermatomyositis, myotonic dystrophies, mitochondrial disorders, muscular dystrophies, and neuropathies. The hairs and the sweat glands are the appendages most frequently affected in neuromuscular disorders. In myotonic dystrophies and mitochondrial disorders there are indications that the rate of skin neoplasms is increased compared with the general population.

CONCLUSIONS

Skin lesions in neuromuscular disorders are not unusual. Neurologists should be aware of the cutaneous implications of neuromuscular disorders and should take a thorough history relative to cutaneous manifestations and complete a comprehensive investigation of the skin and its appendages. If there is evidence of a dermatological problem in a neuromuscular disorder, a dermatologist should be consulted. Dermatological involvement in neuromuscular disorders may contribute to the diagnosis of neuromuscular disorders and may help to differentiate between various entities. The skin should become a focus of the neurologist as well.

Systemic AL amyloidosis with unusual cutaneous presentation unmasked by carotenoderma

We present a case study of an elderly woman with systemic lambda-type AL amyloidosis that featured unusually extensive cutaneous involvement. The case initially presented with a sudden hyper β-carotenemia with carotenoderma that instigated the clinical examination including skin biopsy. A diagnosis of systemic amyloidosis was made. Immunohistochemistry and Western-blot analysis indicated the presence of lambda light chain proteins in skin amyloid deposits. However, notable co-deposition of wild-type apoA-I and transthyretin was observed which caused initial diagnostic confusion. Proteomic analysis of microdissected skin amyloid deposits by mass spectrometry confirmed lambda light chain proteins in amyloid deposits and co-deposition of apolipoprotein A-IV and serum amyloid P-component. The patient died from renal failure caused by amyloid nephropathy combined with analgesic nephropathy. The autopsy disclosed vascular, cardiac, renal and pulmonary amyloid deposition. While all amyloid deposits were positive for lambda light chain proteins, the immunodetection of apoA-I and transthyretin varied significantly among the visceral amyloid deposits. Although the patient exhibited a 1000-fold increase in serum β-carotene levels, only a mild increase in retinol and lutein concentrations was observed. Increased β-carotene values were also found in the liver and the skin. The mechanisms underlying this hyper β-carotenemia remain undetermined.

Scalp seborrheic dermatitis: prevalence and associated factors in male adolescents

BACKGROUND

The prevalence of seborrheic dermatitis (SD) in the general population is variable in the literature. Factors associated with SD are not well understood.

OBJECTIVE

To verify the prevalence of scalp SD in a selected survey of male adolescents on mandatory military service and to find possible associated factors (skin color, socioeconomic level, triceps skin fold, acne, and tobacco consumption).

METHODS

This cross-sectional study included 18-year-old male adolescents on compulsory military service in a southern Brazilian city. Scalp SD was considered as erythema and scaling in any part of the scalp. Skin color, socioeconomic level, triceps skin fold, acne, and tabagism comprised the independent variables studied in our population.

RESULTS

A total of 2201 adolescents entered the study. The global prevalence of scalp SD was 11%. White skin [adjusted prevalence ratio (PR) 1.42; 95% CI 1.06-1.92; P = 0.02] and triceps skin fold >19.5 mm (adjusted PR 1.56; 95% CI 1.12-2.18; P = 0.009) were significantly associated with scalp SD. The other variables were not associated with the outcome.

CONCLUSIONS

Prevalence of scalp SD in our survey of male adolescents was 11%. The occurrence of scalp SD was associated with white skin and a higher body fat content.

Dermatite seborreica

A dermatite seborreica é uma doença eritêmato-escamativa de caráter crônico-recidivante que acomete entre 1 e 3% da população geral dos Estados Unidos. Possui dois picos de incidência - o primeiro, durante os três primeiros meses de vida, e o segundo, a partir da puberdade, atingindo seu ápice entre os 40 e 60 anos de idade. Os indivíduos HIV positivos têm maior prevalência da doença, que apresenta maior intensidade e tendência à refratariedade ao tratamento. Doenças neurológicas e outras doenças crônicas também estão associadas ao desenvolvimento da dermatite seborreica. Como mecanismo fisiopatogênico, reconhece-se que o fungo Malassezia sp., presente na pele de indivíduos suscetíveis, leve a uma irritação não-imunogênica a partir da produção de metabólitos à base de ácidos graxos insaturados deixados na superfície cutânea. Este artigo faz uma revisão da literatura sobre dermatite seborreica, com ênfase nos aspectos imunogenéticos, formas clínicas e tratamento.

Mutilating acral ulcers: the spectrum of differential diagnosis

Prominent acral mutilating ulcers can be present in sensorimotor neuropathies. Although diabetes mellitus is the most common cause of neuropathic ulcers, these skin lesions may manifest in nondiabetic neuropathies. The dermatologic abnormalities may even precede the onset of typical neuropathic symptoms, leading to diagnostic confusion. Therefore, a broad differential diagnosis of neurological and systemic disorders should be considered when evaluating patients who have acral skin ulcerations. We report 3 cases of mutilating ulcers associated with nondiabetic neuropathies. The first case is a woman with multiple ulcerations on her forearm, hands, and toes. Her nerve biopsy revealed neuropathy with multiple congophilic deposits consistent with amyloid neuropathy. The second case is a woman with necrotic painless ulcer on her heel. Nerve biopsy in this patient revealed features suggestive of vasculitic neuropathy. The third case is a man with multiple ulcers on his extremities. A sural nerve biopsy in this patient was consistent with leprous neuropathy.