Gerald Pierard

University of Liège | ulg · Faculty of Medicine

Background Human cutaneous malignant melanoma (CMM) is an aggressive cancer showing a dramatic worldwide increase in incidence over the past few decades. The most prominent relative epidemiological increase has been disclosed in young women. The aim of the study was to assess the effects of chronic sun exposures in order to rate the extend of melan...

In the dermatopathology field, some simple available laboratory tests require minimum equipment for establishing a diagnosis. Among them, the cyanoacrylate skin surface stripping (CSSS), formerly named skin surface biopsy or follicular biopsy, represents a convenient low cost procedure. It is a minimally invasive method collecting a continuous shee...

Human scabies is an ectoparasitosis affecting any individual at any age. The level of infestation by Sarcoptes scabiei var. hominis is influenced by any defect in immune response. Several clinical types of scabies are described including baby scabies, profuse scabies of immunodepression, norvegian scabies and sarcoptic mange. Onchocerciasis dermati...

Senescence of people represents a global expression of obsolescence of their organs, tissues, cells and constitutive molecules. Skin, similarly to any other organ, is ageing in particular ways. Over the past century, the time effects on skin have been expressed differently. Skin of any individual presently engaged in the Third Age looks different f...

Climacteric skin aging affects certain biophysical characteristics of facial skin. The purpose of the present study was to assess the symmetric involvement of the cheeks in this stage of the aging process. Skin viscoelasticity was compared on both cheeks in premenopausal and post-menopausal women with indoor occupational activities somewhat limitin...

The pathophysiology of toxic epidermal necrolysis (TEN) is thought to be related to a drug-induced oxidative stress combined with TNFα overexpression by keratinocytes. None of the current treatments for TEN including systemic corticosteroids, cyclosporine and intravenous administration of immunoglobulins has proven superior over supportive care onl...

Skin ageing occasionally manifests itself at long-term by severe atrophoderma. Systemic or topical corticotherapy exerts an atrophic impact mimicking the effects of old age. Such atrophoderma condition has been described as transparent skin about 40 years ago, and it received more recently the new denomination of dermatoporosis. Such condition stan...

Background: Hypermetabolism and hyposomatotropism related to severe burns lead to impaired wound healing. Growth hormone (GH) boosts wound healing notably following stimulation of the production of insulin-like growth factor-1 (IGF1), a mitogen factor for keratinocytes. Gamma-hydroxybutyrate (GHB) stimulates endogenous GH secretion. Aim: To asse...

Some recently introduced targeted treatments in cancerology are responsible for adverse effects on the skin. These events alter the patient well-being. Adequate dermocosmetic management allows to curb the unwanted skin conditions without interfering with the targeted therapeutic effects. However, evidence-based support for using dermocosmetic produ...

The gravitational syndrome resulting from venous pressure elevation occasionally develops on the legs during pregnancy. The limb tends to enlarge and become stiffer. The body contours are altered. To assess incipient gravitational edema due to chronic venous insufficiency using measurements of the skin tensile strength. A total of 21 women aged 28-...

Striae distensae represent a common skin condition, corresponding to a physiological event particularly developed during adolescence, pregnancy and gain in body weight. In addition, these lesions are induced by the Cushing syndrome or an intense corticotherapy. The viscoelastic properties of the skin are altered and vary according to the severity o...

The frontier between the human body and the environment is largely represented by the stratum corneum. It is obvious that the skin aspect on some body sites appears dry and rough in some predisposed individuals during winter season. The reductions in the outdoor temperature, ambient moisture and dew point are the main physical factors involved in t...

In recent years, clinical dermoscopy has yielded improvement in the early disclosure of various atypical melanocytic neoplasms (AMN). Beyond this approach, histopathology of AMN remains mandatory in the establishment of their precise diagnosis and proper management. Of note, panels of expert pathologists in AMN diagnosis report only moderate agreem...

Endocrine changes supervening after parturition and menopause participate in the control of sebum production and hair growth modulation. The ensuing conditions include some peculiar aspects of hair loss (effluvium), alopecia, and facial hirsutism. The hair cycling is of major clinical relevance because most hair growth disorders result from disturb...

Skin ageing and gender influences on the scalp have been seldom studied. We revisited the changes in the interfollicular scalp. The study was performed on a population of 650 volunteers (300 women and 350 men) for over 7 years. Three age groups were selected in both genders, namely, subjects aged 20-35, 50-60, and 60-70 years. The hair status was f...

Menopause is a key point moment in the specific aging process of women. It represents a universal evolution in life. Its initiation is defined by a 12-month amenorrhea following the ultimate menstrual period. It encompasses a series of different biologic and physiologic characteristics. This period of life appears to spot a decline in a series of s...

Intracellular mitogen-activated protein kinases (MAPK) form a signalling cascade of proteins involved in cell proliferation, differentiation, migration and apoptosis. They are particularly activated by some cytokines, hormones, environmental stress and in skin cancers as well. A series of pharmacological compounds targeting the MAPK cascade dramati...

Climacteric ageing refers to the period of women's life centered by the perimenopause. This step of life is responsible for initiating skin atrophic withering and slackness responsible for changes in the viscoelasticity of the dermal connective tissue. Some women benefit from hormone replacement therapy (HRT) for controlling some unpleasant interna...

Abstract The COL VI mutations are responsible for a spectrum of myopathies. The authors report cutaneous ultrastructural alterations in a patient with COL6A2 myopathy. The changes include variations in size of collagen fibrils, flower-like sections of collagen fibrils, as well as thickening of vessel and nerve basement membranes. Electron microscop...

Ehlers-Danlos syndrome type VIII (EDS-VIII) is a very rare autosomal dominant disease characterized by early-onset periodontitis associated with features of Ehlers-Danlos syndrome. We report a 32-year-old man whose chronic leg ulcer led to the diagnosis of EDS-VIII. He had severe periodontitis with complete loss of permanent teeth and skin fragilit...

Laypeople commonly perceive some skin xerosis and withering (roughness) changes during winter on some parts of the body, particularly on the dorsal hands. The aim of the study was to assess the withered skin surface changes occurring during the four seasons. A total of 47 menopausal women completed the study. A group of 31 volunteers were on hormon...

Circulating sex hormones follow major fluctuations during the ovarian cycle. The so-called premenstrual syndrome represents a global condition grouping the diversity of catamenial disorders. At the skin level, the sebaceous gland activity is obviously modulated by these endocrine fluctuations. In addition, a series of pathological manifestations ta...

Human sweat glands are heterogeneous in their structures and functions. Accordingly, eccrine, apocrine, and apoeccrine glands are distinguished. Some immunohistochemical markers are expected to distinguish the sweat gland types in their secretory and excretory parts. This study used two sets of antibodies. The first panel was composed of antibodies...

Dandruff and seborrheic dermatitis form a continuum of desquamative conditions associated with the excessive colonization of the stratum corneum by yeasts of the genus Malassezia spp. Such colonization is heterogeneous in density, ranging from discrete to abundant according to the fungal ability to adhere to individual corneocytes. The rate of acti...

Introduction: When using adequate wavelength illumination and high resolution recordings, Caucasian skin color appears uneven. The patterns of faint mosaic melanoderma (FMM) are diverse and possibly related to the risk of skin cancer development. Areas covered: The current peer-reviewed publications about objective methods quantifying FMM are re...

From an engineering standpoint, both the skin and subcutaneous tissue act as interconnected load-transmitting structures. They are subject to a variety of intrinsic and environmental influences. Changes in the cutaneous viscoelasticity represent an important aspect in a series of skin conditions. The aim of this work was to explore the methodology...

Drug-induced toxic epidermal necrolysis (TEN) and acute cutaneous graft-versus-host reaction (GVHR) under immunopreventive therapy share some histopathological resemblance. So far, there are no serum biomarkers and no immunohistochemical criteria distinguishing with confidence and specificity the skin lesions of TEN and GVHR. Both diseases present...

Some relationships are established between diabetes mellitus (DM) and a series of cutaneous disorders. Specific dermatoses are markers for undiagnosed DM. Other disorders represent supervening complications in an already treated DM patient. To review the information about dermocosmetic care products and their appropriate use in the management and p...

Marijuana, cannabis, hemp designate some plants and their extracts enriched in cannabinoids including change 9-tetrahydrocannabinol (THC). This soft drug exerts psychoactive effects and is responsible for adverse events appearing on the skin, mucosae and eyes. Contact allergic urticaria possibly occurs as well as Raynaud's phenomenon and arteritis...

The collagen fibril packing that forms threads and bundles is poorly defined, despite the fact that it is important for distinct aspects of the adventitial and reticular dermis. The present study explored an in vitro fibrillogenesis model using the property of heat polymerization. The process was performed on glass slides with mixtures of collagen...

Introduction: A few non-invasive biometrological methods are available for monitoring skin stiffening in systemic scleroderma. Among them, the Cutometer® is used for years by several clinical teams. Objectives: To revisit the microscopic structure of the dermal fibrous networks in scleroderma and the relationship with changes in viscoelasticity....

Introduction: Diabetes mellitus is commonly responsible for skin changes including discrete to mild xerosis. Areas covered: This review focuses on some selected relevant bioinstrumental methods assessing diabetes xerosis. Peer-reviewed articles on objective non-invasive methods were scrutinized. The reviewed methods address i) the xerosis severi...

Scleroderma refers to distinct clinical presentations sharing in common a sclerotic process most often clinically obvious on the skin. The involvement possibly affects the skin alone in morphea or in combination with internal lesions in systemic sclerosis. Some objective and non-invasive functional assessments are useful for better appreciating the...

Some patients suffering from fibromyalgia present with clinical signs and alterations in the histopathology, immunohistochemistry and ultrastructure of the dermis similar to the Ehlers-Danlos syndrome, hypermobile type (EDSH). Some types of fibromyalgia possibly represent an undiagnosed EDSH.

Drug eruptions are frequently encountered and they represent "diseases of medical progress". They are expected in about 2% of treated patients. Their putative diagnosis is based on a set of imputability factors. Several distinct drug-induced skin disorders are identified. They are initially recognized from personal experience, but the implication t...

Toxic epidermal necrolysis (TEN) is a dreadful life-threatening syndrome typically induced by an adverse drug reaction. This condition is characterized by the sudden and extensive destruction of the epidermis. The patient should be promptly addressed to a burn unit where three types of treatment should be administered, namely, (a) specific topical...

Folates are one-carbon donors essential for synthesizing purines, pyrimidines, serine, and methionine. They correspond to anionic hydrophilic molecules essential to DNA synthesis in mammalian cells. The latter cells lack the capacity to synthesize folates. In some patients, high dosages of antifolate drugs (eg: methotrexate, pemetrexed) used in can...

Autosomal recessive cutis laxa type I (ARCL type I) is characterized by generalized cutis laxa with pulmonary emphysema and/or vascular complications. Rarely, mutations can be identified in FBLN4 or FBLN5. Recently, LTBP4 mutations have been implicated in a similar phenotype. Studying FBLN4, FBLN5, and LTBP4 in 12 families with ARCL type I, we foun...

Raynaud's phenomenon is a vascular acrosyndrome caused by a variety of diseases. There is a distinction between the idiopathic Raynaud's disease, the secondary types and the suspicious idiopathic Raynaud's phenomenon.

Fluorescence is a peculiar aspect of photoluminescence. Some intrinsic components of the skin are fluorophores. Other synthetic components are metabolized into fluorophores. These characteristics may be used for identifying some specific aspects of skin physiopathology. Recent technological evolution has provided new devices bringing sensitive and...

Venous leg ulcers have a multifactorial origin. The environmental temperature appears to distinctly modulate the initiation and the subsequent evolution of the leg ulcer. The chronobiology of both episodes is quite distinct. A cold climate favors the initiation while a warmer climate tends to aggravate the ulcer. The seasonal fluctuations of the ul...

The distinction between the Ehlers-Danlos syndrome hypermobile type (EDSH) and the benign joint hypermobility syndrome (BJHS) is unclear. The aim of the present study was to compare skin ultrastructural abnormalities of EDSH and BJHS among different families. Skin of 23 EDSH, 27 BJHS, and 41 asymptomatic subjects from 17 families was examined using...

The homeobox family and its subset of HOX gene products represent a family of transcription factors directing DNA-protein and protein-protein interactions. In the embryo, they are central regulators in cell differentiation during morphogenesis. A series of genes of the four HOX gene clusters A, B, C, and D were reported to show aberrant expressions...

Common bacterial skin infections represent frequent disorders encountered in general practice and in dermatology as well. They encompass a series of infections affecting the epidermis, dermis, hypodermis and subcutaneous tissues. The two main bacteria involved in these processes are Streptococcus pyogenes and Staphylococcus aureus. The resulting in...

Currently, there is no reported objective method allowing confident assessment of hair hydration mapping. Thus, assessing hair moisture kinetics and versatility according to hair shaft damages and hair care products is difficult to perform. To explore a new method for assessing hair moisture. A new method of hair capacitance mapping (HCM) is introd...

For the media and the public at large, malignant melanoma is the most dreadful cancer of the skin. This statement is obvious. However, some nuances merit to be considered. The clinical presentations, histopathology and molecular genetics point to the fact that malignant melanoma is not a single monolithic pathological condition. Different types of...

Psoriasis is a common chronic inflammatory dermatitis mediated by cytokines released by dendritic plasmacytoid cells in combination with Th1- and Th17-cells. This complex and multifactorial condition is commonly associated with some comorbidities. The complexity of a coordinated management of such intricated pathologies is obvious. It calls for the...

Among cancers diagnosed worldwide on a yearly basis, 20% are thought to be associated with a viral infection. The viruses involved are, by order of decreasing incidence, the hepatitis viruses, the papillomaviruses and the Epstein-Barr virus. These virus-induced cancers generate a high level of interest not only for the study of mechanisms involved...

In some patients, psoriasis appears refractory to many treatments, particularly when the disease is confined to some specific body regions. In this respect, palmoplantar psoriasis and palmoplantar pustulosis are possibly related conditions in their immunopathomechanisms involving Il-12, IL-23, and Th17. Nail psoriasis and scalp psoriasis are two ot...

Dermoscopic patterns of basal cell carcinoma (BCC) are well defined, but the dynamics of dermoscopic changes in time were apparently never described so far. In this paper, prominent changes were observed over a 8-week period, allowing to establish a close connection between spoke wheel areas and maple leaf-like aspects, through progressive thickeni...

In recent years, rapid advances were reached in the understanding of a series of biologic signals influencing cutaneous malignant melanoma (CMM) cells. CMM is in close contact with a peculiar dermal extracellular matrix (ECM). Stromal cells store and release various structural ECM components. The impact on CMM growth and progression is mediated thr...

Psoriasis is a chronic relapsing immunoinflammatory dermatosis that is commonly associated with systemic comorbidities. The pathogenic importance of interleukin (IL)-12 and IL-23 is beyond doubt, as well as the involvement of T helper cells (Th)1 and Th17 cells. There is upregulation of the p40 subunit shared by IL-12 and IL-23 and of the IL-23 p19...

Overproduction of sweat, sweaty skin, and body malodors are felt unpleasant by many people in diverse social groups. This review summarizes the functional aspects of the eccrine, apocrine, and apoeccrine sweat glands as encountered in health and disease. A series of measuring methods are conveniently used to explore any trouble in sweat production....

Introduction: Miconazole (MCZ) is a time-honored antifungal of the imidazole class. MCZ exerts a multipronged effect on fungi. It inhibits the cytochrome P450 complex, including the 14α-demethylase enzyme required for ergosterol biosynthesis, in fungal cell membranes. In addition, intracellular accumulation of toxic methylated sterols occurs and t...

Staphylococci are microorganisms often involved in a colonization process on muco-cutaneous sites. They are responsible for various nosocomial and community-associated skin infections. The methicillin-resistant staphylococci are particularly involved in various aspects of pathology. Epidermal antimicrobial peptides are part of the host defense mech...

Both interstitial granulomatous dermatitis (IGD) and palisaded neutrophilic granulomatous dermatitis (PNGD) are rare disorders typically associated with systemic autoimmune conditions. They probably represent different aspects of a disease spectrum encompassing the concept of autoimmunity-related granulomatous dermatitis (ARGD). A 61-year-old woman...

In recent years, the treatment of moderate to severe psoriasis has benefited from the development of targeted biologicals. Assessing this new class of drugs calls for precise modalities of severity/improvement ratings of the disease. Bioengineering-driven dermometrology aims at improving objective and quantitative assessments of disease severity an...

  Rosacea is a chronic inflammatory skin disease affecting mostly facial skin. Its origin is multifactorial. Important steps in its treatment are avoidance of any triggering factor and control of skin inflammation.   To assess the benefit of topical applications of a new product (P-3075).   A randomized, multicenter, double-blind, placebo-controlle...

Psoriasis is a common genetic disorder that may be initiated (drug-induced psoriasis) or exacerbated (drug-triggered psoriasis) by some drug intakes. Beta-blockers, lithium, some antimelarial drugs, non steroidal anti-inflammatory agents and tetracyclines are recognized to influence the clinical course of psoriasis. Other drugs are likely or possib...

Multipotent stem cells of adult skin are found in distinct biological locations identified as niches. These stem cell populations are defined by specific molecular and functional attributes. The epidermal stem cells are found in the interfollicular areas and in the bulge and isthmus of the hair follicles. Dermal stem cells are harbored in the perip...

Treating a patient with cutaneous malignant melanoma relies on the recognition of a clever stratification of the distinct stages of the disease. The histoprognostic criteria were recently revisited. In addition, translational research fueled the development of new treatments with at last increased efficacy in the metastatic stage. Such therapeutic...

For a decade or so, artificial sources of restricted light wavelengths, particularly sunbeds, have progressively gained popularity among adolescents and young adults. Warnings were raised focusing on the risk of accelerated photoaging and photocarcinogenesis. The ULEV (ultraviolet light-enhanced visualization) method is a convenient noninvasive way...

The establishment of the diagnosis of cutaneous malignant melanoma (CMM) always calls for histopathological confirmation. Further to the recognition of the CMM aspects, immunohistochemistry is helpful, in particular, in determining the size of the replicative compartment and the activity in each of the cell cycle phases (G 1 , S, G 2 , M). The invo...

In some instances, a dermatosis exhibits a rapid and focal surge of seemingly similar tiny lesions. We report a few typical exemples occurring in adolescents.

Primary cicatricial alopecias (PCA) result from the inflammatory destruction of the hair follicle, followed by its replacement by a fibrotic streamer. The involvement of multipotent stem cells of the hair follicle is possible through a transdifferentiation pathway. The diagnosis relies on clinico-pathologic correlations. PCA are classified as the n...

At present, immunohistochemistry is taken for granted in the establishment of malignant melanoma (MM) diagnosis. In recent years, molecular diagnosis in dermatopathology has benefited from a vast array of advances in the fields of genomics and proteomics. Sensitive techniques are available for detecting specific DNA and RNA sequences by molecular h...

Malignant melanoma (MM) is one of the most aggressive skin cancer. The therapeutic options remain limited for advanced MM, and those directed to the neoplastic cells have not brought major survival advantage so far. Immunotherapy is another targeted option. Ipilimumab, a monoclonal antibody directed to CTLA-4 present on cytotoxic T cells boosts imm...

The fund of knowledge regarding the versatility of presentation of MM metastases is still quite incomplete. The recent literature pertaining to the current understanding of the mechanisms underlying two special features of MM metastasis is reviewed. On the one hand, a long disease-free interval (MM dormancy) may occur before the surge of overt meta...

During malignant melanoma (MM) progression including incipient metastasis, neoplastic cells follow some specific migration paths inside the skin. In particular, they progress along the dermoepidermal basement membrane, the hair follicles, the sweat gland apparatus, nerves, and the near perivascular space. These features evoke the thigmotropism phen...

Infantile haemangioma therapy has long been a wait-and-see policy. Since recent development of laser and light therapy, pulsed dye laser has been successfully used for treating superficial haemangiomas. Few studies have been published about treatment with intense pulsed light (IPL) to assess the risk/benefit of IPL in the treatment of infantile hae...

Cancer patients under targeted chemotherapy to the epidermal growth factor receptor (EGFR) frequently suffer from unusual skin adverse events. In the past, these changes were globally qualified as a rash. Our aim was to assess objectively by non invasive bioinstrumentation some early structural and functional skin changes associated with EGFR inhib...

  With aging, the barrier repair kinetics following any weakening of the epidermal permeability barrier function is commonly slowed down.   To assess the recovery rate of the epidermal permeability barrier function following controlled stripping and applications of samphire and control formulations.   In 12 healthy subjects older than 50 years, con...

Mottled subclinical melanoderma (MSM) is frequently seen on facial skin using the ultraviolet light enhanced visualization (ULEV) method. The corresponding aspect on the hairless scalp remains unknown. To explore the field distribution of melanin on the scalp of fair-skinned Caucasian subjects. The scalp was examined in 43 men with androgenic alope...

Some parasitic or pathogen fungi for pet skin are possibly transmitted to humans in whom they are responsible for superficial mycozoonoses. Cats, dogs and some small rodents are commonly involved. The lesions correspond to glabrous skin dermatophytoses and to microsporic tinea of the scalp. These disorders represent the vast majority of the prevale...

Hypomelanosis of Ito is a rare genetic disorder characterized by whorled areas of hypomelanosis. The purpose of the present study was to revisit some aspects of Ito's hypomelanosis. Clinical observations included ultraviolet-light-enhanced visualization (ULEV) method. Histochemistry, immunohistochemistry, and electron microscopy were performed on b...

Palmoplantar keratodermas affect a vast group of the population. Their origin is genetic or acquired. They represent manifestations of several distinct diseases. The precise semiologic examination is important for elucidating the differential diagnosis.

The versatility of the clinical presentations of syphilis is large. A laboratory diagnosis is required in any case where a clinical assumption is raised. Two main diagnostic methods are available according to the lesion aspects and the staging of the disease. They rely on the recognition of the spirochete or on the identification of the immune resp...

Pemetrexed (Alimta®) is a multitargeted antifolate drug approved as a single agent or in combination with cisplatin for the treatment of a small number of malignancies including advanced and metastatic non-squamous non-small cell lung cancer (NSCLC), and malignant pleural mesothelioma. This review reports the recent peer-reviewed publications and o...