[CME Dermatology 24: Porokeratosis]

CME Dermatology 24: Porokeratosis Abstract. Porokeratoses are a heterogeneous group of cornification disorders with the characteristic histological feature of the cornoid lamellae in the area of the marginal ridge. It is a rare but characteristic disease that occurs primarily in adulthood. Men are slightly more likely to be affected. The etiopathogenesis that leads to the transformation of the keratinocytes remains unclear; associations with genetic mutations and trigger factors such as UV rays and immunosuppression were observed. Due to the risk of malignant degeneration, consistent sun protection and regular clinical controls should take place. Cryotherapy, ablative laser therapy, curettage, photodynamic therapy or topical application of fluorouracil (5-FU), imiquimod and retinoids can be used to treat itchy, painful or cosmetically disturbing porokeratoses, depending on the location and severity.

[CME Dermatology 24/Answers: Porokeratosis]

CME Dermatology 24/Answers: Porokeratosis Abstract. Porokeratoses are a heterogeneous group of cornification disorders with the characteristic histological feature of the cornoid lamellae in the area of the marginal ridge. It is a rare but characteristic disease that occurs primarily in adulthood. Men are slightly more likely to be affected. The etiopathogenesis that leads to the transformation of the keratinocytes remains unclear; associations with genetic mutations and trigger factors such as UV rays and immunosuppression were observed. Due to the risk of malignant degeneration, consistent sun protection and regular clinical controls should take place. Cryotherapy, ablative laser therapy, curettage, photodynamic therapy or topical application of fluorouracil (5-FU), imiquimod and retinoids can be used to treat itchy, painful or cosmetically disturbing porokeratoses, depending on the location and severity.

Linear porokeratosis associated with multiple squamous cell carcinomas

Linear porokeratosis is a rare subtype of porokeratosis with a higher rate of malignant transformation than other subtypes of porokeratosis. Identification of cornoid lamellae on histology allows for definitive diagnosis, which makes high clinical suspicion and appropriate biopsy essential in establishing the correct diagnosis and developing an effective management plan. We present a case report of linear porokeratosis and discuss aspects of etiology, diagnosis, and management.

Eruptive disseminated porokeratosis associated with internal malignancies: a case report

Porokeratosis is a chronic skin disorder characterized by the presence of patches with elevated, thick, keratotic borders histologically featuring cornoid lamella. While porokeratosis usually is clinically defined by a slow onset, an eruptive variant has been reported. We report a 77-year-old woman affected by pancreatic carcinoma with-eruptive disseminated porokeratosis (EDP). We reviewed published cases of EDP developing suddenly or within a few months and found a total of 16 patients, 6 with internal malignancies of the liver or gastrointestinal tract. These findings suggest that patients with EDP should be investigated for the presence of internal malignancies.

Linear porokeratosis: a case report and review of the literature

Linear porokeratosis refers to 1 of 5 variants of porokeratosis. Porokeratosis is a keratinization disorder of multiple etiologies including genetic aberrancy, trauma, and infection. We review a case of a 35-year-old man with a chronic history of linear porokeratosis and conduct a review of porokeratosis subtypes, etiology, histology, pathology, differential diagnosis, and treatment.

An unusual patient with Rothmund-Thomson syndrome, porokeratosis and bilateral iris dysgenesis

Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive genodermatosis characterized by poikiloderma and the variable presence of other features including skeletal and ocular abnormalities, ectodermal defects, and susceptibility to certain malignancies. We report a 40-year-old woman with known RTS who developed porokeratoses on her limbs in adulthood, an association that has not previously been reported. In addition, she had bilateral iris dysgenesis, which has only been described once before in RTS.

Porokeratotic eccrine ostial and dermal duct nevus

Porokeratotic eccrine ostial and dermal duct nevus is a rare disorder characterized by distinctive histopathology. We describe a 6-year-old boy who had the typical palmar involvement and small discrete areas involving the midline of his back.

Porokeratosis of Mibelli following bone marrow transplantation

BACKGROUND

Porokeratosis is a rare disorder of keratinization with both autosomal dominant and acquired forms. Immunosuppression has been associated with the development of porokeratosis in numerous case reports and series. To our knowledge, however, only five cases of porokeratosis have been reported following bone marrow transplantation.

RESULTS

We report five cases of porokeratosis of Mibelli following bone marrow transplantation. The diagnosis of porokeratosis was made between 1 and 13 years post-transplantation. The underlying malignancy in four of the five cases was leukemia, while the fifth patient had non-Hodgkin's lymphoma. Porokeratosis developed during remission in the four leukemia patients, whereas, in the fifth patient, it occurred during a relapse of lymphoma.

CONCLUSIONS

Porokeratosis may develop following bone marrow transplantation. Our five cases double the number reported in the medical literature, and the incidence of porokeratosis following bone marrow transplantation may be significantly higher than previously recognized. As cutaneous carcinomas have been reported in association with porokeratosis, careful surveillance for porokeratosis in bone marrow transplant recipients is warranted.

Porokeratosis plantaris, palmaris, et disseminata

A 66-year-old woman presented with thick, hyperkeratotic papules and plaques on the plantar aspects of both feet as well as more superficial, annular, hyperkeratotic papules on the chest, neck, and face. A biopsy was consistent with porokeratosis. The clinical findings are consistent with porokeratosis plantaris, palmaris, et disseminata.

Porokeratosis of the lower lip

The porokeratoses are defined as specific disorders of keratinization that are histologically characterised by the presence of a dense, parakeratotic column, well-circumscribed from the rest of the corneocytes, known as the cornoid lamella. In this article, we report two cases of porokeratosis of the lower lip, drawing attention to the unusual site. We also emphasize the clinical appearance of these lesions, which may easily be misdiagnosed if not examined correctly. As a consequence of this misdiagnosis, the prevalence of these lesions is probably greater than at present estimated. Moreover, a good response to cryotherapy is shown.

Successful treatment of porokeratosis with 585 nm pulsed dye laser irradiation

Porokeratosis, a keratinization and fibroblast cutaneous disorder, is a progressive disease with limited treatment options. We describe a case of linear porokeratosis that responded favorably to a series of 585 nm pulsed dye laser treatments. In addition to its vascular specificity, the pulsed dye laser presumably produces a direct effect on collagen, as well as an indirect effect on histamine and mast cells that could account for the clinical changes seen in our patient.

Vulvar porokeratosis: case report and review of the literature

We report the first case of vulvar porokeratosis that occurred in a 39-year-old woman with a 30-year history of vulvar pruritus and disfiguring vulvar lesions. Ultrasonic surgical aspiration resulted in resolution of her pruritus and excellent cosmesis. Light microscopy revealed characteristic cornoid lamellae and electron microscopy confirmed the diagnosis of vulvar porokeratosis.

A report of 31 cases of porokeratosis at the National Skin Centre

Porokeratosis is a well-recognised disorder of keratinization with distinctive clinical features and histological hallmark of cornoid lamella. There are at least 4 different clinical variants, with malignant transformation reported in almost all types of porokeratosis. This is a retrospective study on all cases of porokeratosis seen at the National Skin Centre, Singapore from 1990 to 1993. There was a total of 31 patients diagnosed to have porokeratosis during the study period. They can be classified into 4 main clinical variants: (1) disseminated superficial actinic porokeratosis (41.9%), (2) classical porokeratosis of Mibelli (35.5%), (3) porokeratosis palmaris, plantaris et disseminatum (9.7%), and (4) linear porokeratosis (12.9%). Our typical patient is in his/her early forties, who noticed asymptomatic porokeratotis lesion on sun-exposed skin. Various treatment modalities were used, with no one method being more superior to another. None of our patients had malignant transformation of pre-existing skin lesions during the short follow-up period from less than one year to three years. Patients should be advised to avoid excessive sunlight, to use sunscreen and go for periodic examination by a dermatologist with a view to close skin malignancy surveillance.