High incidence of porokeratosis in renal transplant recipients

Porokeratosis: An enigma beginning to unravel

Porokeratosis is a keratinization disorder with unclear etiopathogenesis, varied clinical presentation and characteristic histopathology, and is usually unresponsive to current therapeutic options. Until now, it was considered to be a clonal disorder with immunity, ultra violet radiation and other factors playing important roles in etiopathogenesis. It is now known that abnormalities in the mevalonate pathway are responsible for this clonal keratinization abnormality. New variants of porokeratosis like eruptive bullous, pruriginous, lichen planus like, follicular variants and porokeratoma have been described. While the cornoid lamella is the classical histopathologic feature, dermoscopy and reflectance confocal microscopy make the diagnosis clearer. Development of malignancy in a few variants is a concern. Linear, disseminated superficial actinic and giant lesions are most prone to developing malignancies. Bowen's disease, squamous cell carcinoma, basal cell carcinoma and even melanoma have been reported in cases of long-standing porokeratosis. Newer modalities of therapy such as photodynamic therapy, ingenol mebutate and HMGCoA inhibitors may play a role in the future.

Three-dimensional aspects of superficial disseminated porokeratosis with scanning electron microscopy

The three-dimensional findings of the surface and from a cross section from a case of disseminated superficial porokeratois using scanning electron microscopy are reported. On the surface of the skin, irregular keratin with a serpiginous distribution was seen. A gross aspect of keratin in the hyperkeratotic wall was also observed and compared to the normal area, in which the release of corneocytes seemed normal. The cross-sectional imaging easily identified the cornoid lamella, with compact keratin surrounded by normal stratum corneum.

Clinical analysis and etiology of porokeratosis

The present study was performed in order to define the clinical manifestations of porokeratosis, with particular emphasis on genital porokeratosis. A total of 55 cases of porokeratosis were retrospectively reviewed between 2000 and 2007 from Huashan Hospital (Shanghai, China). Out of 55 cases, there were 22 cases of porokeratosis of Mibelli, 17 cases of disseminated superficial actinic porokeratosis (DSAP), 15 cases of disseminated superficial porokeratosis and one case of linear porokeratosis. The ratio of males to females was 39:16. Among them, 12 cases had a family history of porokeratosis. During the five-year follow-up period, no malignant transformation was observed and no further aggravation of lesions was detected. The results indicated that the initial region of DSAP in the Chinese population may differ from Caucasians. In combination with other studies, the present study found that genital porokeratosis in the Chinese population is often associated with pruritus. Since no recurrence was observed in cases treated with surgical excision, it was suggested that surgical excision is a viable treatment strategy and should be used for porokeratotic lesions if possible. In addition, regular follow-ups are required, since the aggravation of porokeratosis may cause the development of malignancy transformation.

Atypical porokeratosis developing following bone marrow transplantation in a patient with myelodysplastic syndrome

Porokeratosis is an abnormal disease of keratinization of epidermis. It is clinically characterized by margins covered with keratin layer and it typically has an atrophied macule with a protruded, circular form. Histopathologically, it shows the findings of cornoid lamella. Risk factors for its development include organ transplantation, long-term use of corticosteroids, immunocompromised status, including AIDS, and exposure to ultraviolet light. We herein report a case of atypical porokeratosis in a 38-year-old man who developed porokeratosis involving multiple sites following bone marrow transplantation for myelodysplastic syndrome.

Clinical Study of Porokeratosis Associated with Immunosuppressive Therapy in Renal Transplant Recipients

BACKGROUND

The etiology of porokeratosis (PK) remains unknown, but immunosuppression is known to be a factor in the pathogenesis of PK and it may also exacerbate PK.

OBJECTIVE

The aim of this study was to examine the clinical characteristics of PK associated with immunosuppressive therapy in renal transplant recipients.

METHODS

A total of 9 renal transplant patients diagnosed with biopsy-proven PK from January 2001 to December 2006 were enrolled. The authors analyzed the patient and medication histories, clinical characteristics, and associated diseases.

RESULTS

The ages of the 9 patients ranged from 38 to 67 years (mean 52 years). All received multi-drug regimens comprised of two or three immunosuppressive agents (steroids, cyclosporine, mycophenolate mofetil, azathioprine and/or tacrolimus). Times between transplantation and the onset of PK ranged from 2 to 9 years (mean 4.1 years). No family history of PK or a history of intense sun-exposure was elicited. The number of the lesions was less than ten in 8 of the 9. Lesions were mainly located in the extremities, though some affected the trunk or neck (3). Three patients had disseminated superficial actinic PK (DSAP), PK Mibelli, or both types. Associated diseases included verruca (4), recurrent herpes simplex (1), actinic keratosis (1), and cutaneous B cell lymphoma (1).

CONCLUSION

The three clinical patterns of PK occurred equally in our patients, namely, coexistent PK Mibelli and DSAP, or the DSAP and Mibelli types as independent forms. Our findings support the notion that the different variants of PK be viewed as parts of a heterogeneous clinical spectrum. Further studies are needed in order to establish the clinical patterns of PK in immunosuppressed patients.

[Porokeratosis in a patient with dermatomyositis]

There are several reports of porokeratosis in the context of immmunosuppressive diseases. These mainly include organ transplant, HIV infection, lymphomas and some inflammatory and autoimmune diseases commonly treated with immunosuppresive drugs or chemotherapy. Disseminated superficial actinic porokeratosis is the clinical variant of porokeratosis that most frequently develops in immunosuppressive states. We report a case of porokeratosis in a woman with dermatomyositis.

Fatal squamous cell carcinoma arising from transplant-associated porokeratosis

Porokeratosis is a disorder of epidermal keratinization characterized by variably sized plaques with central depression and a well-demarcated keratotic border. Associations of porokeratosis with immunosuppression and of porokeratosis with malignancy have been observed. The authors report a case of fatal metastatic squamous cell carcinoma arising from porokeratosis in an immunosuppressed patient.

Disseminated superficial actinic porokeratosis with both typical and prurigo nodularis-like lesions

We report a 50-year-old Korean patient who developed a disseminated superficial actinic porokeratosis (DSAP) with two types of lesions. One was a typical DSAP lesion clinically and histopathologically. The other was clinically similar to prurigo nodularis, but histologic examination showed the findings of porokeratosis such as cornoid lamellae and loss of the granular layer in addition to those of chronic lichenified dermatitis, so it could be described as prurigo nodularis-like porokeratosis. The nodular lesions seemed to develop on preexisting typical lesions of DSAP mainly during the summer by the aggravation of pruritic symptoms and scratching associated with sun exposure. Although we could not find any published reports describing lesions like those of our case, we think that such prurigo nodularis-like porokeratosis can develop in patients with DSAP in some situations involving pruritus and scratching.

An unusual presentation of dermatomyositis: the type Wong variant revisited

We describe a 53-year-old white woman with dermatomyositis (DM) who had additional clinical findings of pityriasis rubra pilaris (type Wong dermatomyositis) with histopathologic features of both pityriasis rubra pilaris (PRP) and porokeratosis. Type Wong dermatomyositis was originally described in 11 patients by Wong in 1969 and has been reported in 5 additional patients. This is a rarely described phenomenon in which patients with DM develop cutaneous hyperkeratotic lesions that resemble PRP and histologically show follicular hyperkeratosis and hair follicle destruction. Arrector pilorum muscles also show degenerative findings and myositis. We believe that this is the first reported case of a patient with type Wong DM who also has clinical and histologic features suggestive of porokeratosis. This is important because of the association of adult-onset dermatomyositis with internal malignancy and the well-documented association of porokeratosis with immunosuppression. These clinical and histologic findings serve as markers for malignancy in patients with DM. These patients warrant a complete review of systems and investigation for age-appropriate neoplasms as well as close long-term follow-up by dermatologists to ensure that these cutaneous eruptions are not overlooked.

Sudden onset of disseminated porokeratosis of Mibelli in a renal transplant patient

Porokeratosis is a disorder of epidermal keratinization of uncertain cause. Five clinical variants of porokeratosis have been described. These include porokeratosis of Mibelli, punctate porokeratosis, linear porokeratosis, porokeratosis palmaris plantaris et disseminata, and disseminated superficial porokeratosis. Disseminated superficial porokeratosis and single plaque porokeratosis of Mibelli have each been documented to occur in association with immunosuppression. To our knowledge, only 5 cases of disseminated porokeratosis of Mibelli in transplant recipients have been reported. We present a patient who developed explosive onset of disseminated porokeratosis of Mibelli shortly after renal transplantation. It is important to differentiate this unusual variety of porokeratosis from other cutaneous manifestations in transplant patients so that appropriate therapy can be instituted.