Reactive perforating collagenosis: a condition that may be underdiagnosed

Cutaneous manifestations of ESRD

A broad range of skin diseases occurs in patients with ESRD: from the benign and asymptomatic to the physically disabling and life-threatening. Many of them negatively impact on quality of life. Their early recognition and treatment are essential in reducing morbidity and mortality. The cutaneous manifestations can be divided into two main categories: nonspecific and specific. The nonspecific manifestations are commonly seen and include skin color changes, xerosis, half-and-half nails, and pruritus. The specific disorders include acquired perforating dermatosis, bullous dermatoses, metastatic calcification, and nephrogenic systemic fibrosis. This review article describes these conditions and considers the underlying pathophysiology, clinical presentations, diagnosis, and treatment options.

Acquired reactive perforating collagenosis: current status

Acquired reactive perforating collagenosis is a unique perforating dermatosis, characterized clinically by umbilicated hyperkeratotic papules or nodules and histologically by a focal hyperkeratosis in direct contact with transepidermal perforating dermal collagen. Several inflammatory or malignant systemic diseases may coexist with acquired reactive perforating collagenosis. The possible biochemical or immunological mechanisms of the systemic diseases, potentially responsible for the development and appearance of acquired reactive perforating collagenosis, are still under investigation. Several topical treatments, ultraviolet B phototherapy and allopurinol p.o. administration may be effective.

Laser-induced transepidermal elimination of dermal content by fractional photothermolysis

The wound healing process in skin is studied in human subjects treated with fractional photothermolysis. In-vivo histological evaluation of vacuoles formed over microthermal zones (MTZs) and their content is undertaken. A 30-W, 1550-nm single-mode fiber laser system delivers an array of 60 microm or 140 microm 1e2 incidence microbeam spot size at variable pulse energy and density. Treatments span from 6 to 20 mJ with skin excisions performed 1-day post-treatment. Staining with hematoxylin and eosin demonstrates an intact stratum corneum with vacuolar formation within the epidermis. The re-epithelialization process with repopulation of melanocytes and keratinocytes at the basal layer is apparent by 1-day post-treatment. The dermal-epidermal (DE) junction is weakened and separated just above zones of dermal coagulation. Complete loss of dermal cell viability is noted within the confines of the MTZs 1-day post-treatment, as assessed by lactate dehydrogenase. All cells falling outside the irradiation field remain viable. Content within the epidermal vacuoles stain positively with Gomori trichrome, suggesting a dermal origin. However, the positive staining could be due to loss of specificity after thermal alteration. Nevertheless, this dermal extrusion hypothesis is supported by very specific positive staining with an antihuman elastin antibody. Fractional photothermolysis creates microthermal lesions that allow transport and extrusion of dermal content through a compromised DE junction. Some dermal material is incorporated into the microepidermal necrotic debris and shuttled up the epidermis to eventually be exfoliated through the stratum corneum. This is the first report of a nonablative laser-induced transport mechanism by which dermal content can be predictably extruded biologically through the epidermis. Thus, treatment with the 1550-nm fiber laser may provide the first therapeutic option for clinical indications, including pigmentary disorders such as medically recalcitrant melasma, solar elastosis, as well as depositional diseases such as mucinosis and amyloidosis.

Amifostine administration during radiotherapy for cancer patients with genetic, autoimmune, metabolic and other diseases

Amifostine is a broad-spectrum cytoprotective agent approved for protection against cisplatin toxicities and radiation-induced xerostomia; strong clinical evidence exists that amifostine protects normal mucosa and lung from radiation damage. Hypotension, nausea/vomiting, fatigue and fever/rash are the main side-effects associated with amifostine administration. The present study summarizes our experience on daily amifostine administration to cancer patients with various coexisting medical conditions and diseases. The tolerance and the eventual interference of amifostine with the course of the coexisting diseases is reported, providing a core list of medical conditions met in radiotherapy practice, their compatibility with amifostine administration and recommendations on how to deal with these patients. This list comprises genetic diseases (xeroderma pigmentosum, glucose-6-phosphate dehydrogenase deficiency), autoimmune disorders (vitiligo, scleroderma, thyroiditis, perforating collagenosis), metabolic diseases (diabetes mellitus), cardiovascular diseases, neuro/psychiatric diseases and other medical conditions (hypoglycemia, hepatic cirrhosis, alcoholism). A high incidence of fever/rash was noted in patients with autoimmune diseases, while all other conditions did not alter the patterns of side-effects expected following amifostine administration.

Reactive perforating collagenosis associated with scabies in a diabetic

Reactive perforating collagenosis (RPC) in adults commonly manifests in patients with diabetes mellitus. Pruritus and consequent induced scratching have been identified as the bases for the evolution of this skin disease. We present the unusual case of a 55-year-old female diabetic with characteristic umbilicated skin lesions and a long history of scabies. Histology from a crusty nodule revealed transepidermal elimination of collagen. Following antiscabietic treatment, two courses of oral doxycycline demonstrated beneficial effects in controlling the perforating skin disorder.