Porokeratosis of Mibelli: Successful Treatment with Cryosurgery

Porokeratoses-A Comprehensive Review on the Genetics and Metabolomics, Imaging Methods and Management of Common Clinical Variants

Porokeratosis is a heterogeneous group of keratinising disorders characterised by the presence of particular microscopic structural changes, namely the presence of the cornoid lamella. This structure develops as a consequence of a defective isoprenoid pathway, critical for cholesterol synthesis. Commonly recognised variants include disseminated superficial actinic porokeratosis, disseminated superficial porokeratosis, porokeratosis of Mibelli, palmoplantar porokeratosis (including porokeratosis palmaris et plantaris disseminata and punctate porokeratosis), linear porokeratosis, verrucous porokeratosis (also known as genitogluteal porokeratosis), follicular porokeratosis and porokeratoma. Apart from the clinical presentation and epidemiology of each variant listed, this review aims at providing up-to-date information on the precise genetic background, introduces imaging methods facilitating the diagnosis (conventional and ultraviolet-induced fluorescence dermatoscopy, reflectance confocal microscopy and pathology), discusses their oncogenic potential and reviews the literature data on the efficacy of the treatment used, including the drugs directly targeting the isoprenoid-mevalonate pathway.

Porokeratosis: A Review of Its Pathophysiology, Clinical Manifestations, Diagnosis, and Treatment

Porokeratosis comprises a group of heterogeneous and uncommon acquired or congenital skin diseases of unknown origin characterized by a keratinization disorder resulting from abnormal clonal expansion of keratinocytes. Numerous genetic mutations are thought to be involved. These conditions are characterized histologically by the presence of a cornoid lamella. Clinical manifestations are variable, with localized, disseminated, and even eruptive forms. Porokeratosis has been associated with immunosuppression, ultraviolet radiation, and systemic, infectious, and neoplastic diseases. Many authors consider it to be a premalignant condition because of the potential for malignant transformation to squamous cell or basal cell carcinoma. Therefore, long-term follow-up is a key component of treatment, which is usually complex and often unsatisfactory. We review the latest advances in our understanding of the pathogenesis, diagnosis, and treatment and propose a treatment algorithm.

Treatment of Porokeratosis: A Systematic Review

BACKGROUND

Porokeratosis (PK) is a rare skin disease of unknown etiology. It consists of a keratinization disorder, which may appear in several clinical forms and can undergo malignant transformation. The histopathological hallmark of PK is the cornoid lamella. While many topical, systemic, and surgical treatment modalities for PK have been described, no randomized controlled trials have been performed yet. Because of a lack of treatment standards for PK, European and international guidelines cannot be created.

OBJECTIVE

The aim of this systematic review is to outline options for treating PK.

METHODS

We performed a systematic literature search in an electronic database for published literature. A total of 88 articles fulfilling our inclusion criteria were found.

RESULTS

There were no randomized controlled trials on the treatment of PK, but mainly case reports and case series. Porokeratosis of Mibelli showed the best outcomes after treatment with imiquimod cream and linear PK responded well to topical or systemic retinoids. Topical vitamin D acid derivatives may be the best therapeutic option for disseminated PK. Surgical interventions and cryotherapy may be preferred in areas where the use of topical agents is difficult or contraindicated.

CONCLUSION

To offer patients with PK an evidence-based high-quality standardized therapy, randomized controlled trials are needed.

Recalcitrant Digital Porokeratosis of Mibelli: A Successful Surgical Treatment

Context:

Porokeratosis of Mibelli (PM) is a rare, benign, asymptomatic, epidermal hyperkeratinization dermatitis that is characterized by annular plaque that expands through the edges and leaves an atrophic center. Many therapies have been attempted for the treatment of PM, but none of these have given satisfactory results. The efficacies of treatment options are limited, and currently there is no gold standard.

Case Report:

This paper reports the case of a 22-year-old female with 3-years history of PM, who had not responded to routine therapies like topical corticosteroids, topical tretinoin, topical salicylic acid, and various emollients and keratolytic agent. Cryosurgery and laser ablation did not have acceptable response. We used surgical treatment with successful cosmetic outcome.

Conclusion:

The treatment of PM should be individualized considering the aesthetic and functionality, and the patient's preferences. Complete surgical excision for isolated digital PM had good results.

Linear porokeratosis: a case report

Porokeratosis is a rare genodermatosis based on chronic keratinization disorder histologically characterized by the presence of a cornoid lamella and various clinical manifestations. Five most commonly described types of poroketarosis are porokeratosis of Mibelli or ”classic” porokeratosis, disseminated superfi cial actinic porokeratosis, disseminated palmoplantar porokeratosis, linear porokeratosis, and punctate porokeratosis. In all of the fi ve clinical types of porokeratosis described today, cases of planocellular skin carcinoma are described, except in punctate type cases. Use of topical CO2 laser ablation, cryotherapy and topical use of 5% Imiquimod cream, have shown favorable effects in local treatment of porokeratosis. The authors present a clinical case of a girl suffering from linear porokeratosis over the course of the last four years, spreading on the inside of her right arm along the lines of Blaschko. Linear porokeratosis was histologically confi rmed by biopsy of skin lesions and dermoscopy. Dermoscopic fi ndings, used as an auxiliary method, also indicated linear porokeratosis. Successful liquid nitrogen cryotherapy prompted the authors to present a case in which the applied treatment proved to be successful, but also to emphasize the need for timely treatment in order to prevent malignant alterations of these changes.

A case of inflammatory disseminated superficial porokeratosis in a colon cancer patient

Disseminated superficial porokeratosis (DSP) is a specific disorder of keratinization. Genetic studies show that DSP is an autosomal dominant trait. Clinically, the lesions show a sharply demarcated and hyperkeratotic plaque with central atrophy. The lesions appear mainly in the extremities and generally develop with bilateral symmetry. Unusual cases of DSP accompanied by severe pruritus have been reported as "eruptive pruritic papular porokeratosis" or "inflammatory DSP." Histopathologically, inflammatory DSP is characterized by the presence of cornoid lamella with a dense infiltration of eosinophils and lymphocytes in the perivascular area of the upper dermis. Here we report a case of inflammatory DSP in a 84-year-old man with colon cancer who presented with multiple hyperpigmented atrophic macules.

Giant verrucous porokeratosis of Mibelli mimicking psoriasis in a patient with psoriasis

Porokeratosis of Mibelli is a disorder of epidermal keratinization characterized by annular plaques with an atrophic center surrounded by a keratotic wall. We report a case of a giant verrucous porokeratosis of Mibelli mimicking psoriasis that developed in a patient with psoriasis and therefore went unrecognized for a long time. Histologically the lesion combined features of porokeratosis at the periphery and of psoriasis at its center, a picture recently described as "psoriasis encircled by porokeratosis." The possible pathogenetic relationship between psoriasis and the development of porokeratosis is also discussed.