HPV by electron microscopy
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see also: close-up of foot
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Rabbit with parallel condition
caused by Shope papillomavirus
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Lewandowsky-Lutz is a collection of hard growths on the skin caused by keratin-producing, virally-induced skin dysplasias. These usually occur on the hands and feet. The disease was formerly known as "epidermodysplasia verruciformis of Lewandowsky and Lutz," after two German dermitologists of the early 20th century. It is now officially named just epidermodysplasia verruciformis (EV). The growths are normally small and flat but may be large and horn-like (as in the accompanying photos), and they may eventually develop into full neoplasias.
Papillomaviridae
Lewandowsky-Lutz/EV is caused by the human papillomavirus (HPV), a Baltimore Group I (dsDNA) virus. HPV reproduces in the keratinocytes of the skin, and various strains are adapted to live in specific parts of the body (e.g., genitals, hands and feets, etc). About 15 of the hundred HPV strains typically cause EV and, of these, 4 lead to cancers. HPV types 5 and 8 appear in 90% of the EV squamous cell carcinomas.
Red macules on the hands, feet, face or trunk usually first occur between childhood and early adulthood. Over decades, these can develop into yellow or blue-gray papules producing varying amounts of keratin. The dysplasias may develop into squamous cell carcinoma in the patient's 40s and 50s.
EV is thought to be caused by a problem in the cell-mediated response to viral infection: T-lymphocytes do not respond to mitogens, and there is a decreased hummoral response. In addition, there is a high correlation with patients who have decreased IL-10 production. Ultraviolet radiation seems to play some role in the late-life transformation into carcinomas, and growths exposed to sunlight are usually the first to become cancerous. Additionally, patients with acquired (as opposed to inherited) immunocompromise seem to be more susceptible to cancers.
Transmission: Non-immunocompromised people are thought to be immune to disease by infection with HPV strains that cause EV. Genetic inheritance (mostly autosomal recessive) is a typical mode of the immunocompromise, although EV has also been found in HIV patients and organ transplant patients. HPV is normally transmitted by direct contact with infected tissue.
Clinical diagnosis of EV is usually made based on morphology. However, research also indicates a high level of growths with pathogenic tissue characteristics that are not detectable visually. Molecular diagnostic techniques such as polymerase chain reaction and restriction fragment length polymorphism can be used to identify fragments of viral DNA.
Microscopy: Slices of a biopsied growth will show viral particles via electron microscopy and viral antigens via fluorescent antibody staining.
Infection with the HPV virus is an incurable, life-long condition. EV growths can be removed using the treatments typical for common warts, but almost always recur. Complete removal of infected skin and prevention of recurrence with surgical excision and skin grafting has been reported in the Chinese Journal of Plastic Surgery and Burns.
Some chemotherapy treatments are possibly helpful. Recently, Acitretin and Interferon alfa-2a were reported to have positive results.
The recent development of the HPV vaccine to prevent cervical cancer and the successful vaccination of rabbits against their analogous Shope papillomavirus both suggest that a vaccine against EV may be viable.