Pterygium unguis formation in porokeratosis of Mibelli

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 of the Nail Unit: Case Series and Review

Background

The lesions of porokeratosis (PK) lead to skin atrophy and scarring as long as they spread centrifugally. PK affecting the nail unit is seldom described.

Objective

The aim was to revise the previously reported cases of ungual PK and to present 3 new cases.

Methods

A PubMed search was performed with the keywords "nail" and "porokeratosis." Previously reported cases as well as 3 new cases are depicted in tables.

Results

Only 11 cases of ungual PK were found; 3 new cases have been added. All patients presented with typical lesions of PK (Mibelli, isolated, segmental, or ostial eccrine types) that happened to affect nails due to nail matrix or nail bed compromise, resulting in mild to severe nail scarring, including irreversible anonychia. The present 3 case series contrast with the previous single case reports.

Conclusions

PK affecting the nails is exceedingly rare. Changes in nails affected by PK are irreversible, since, as on the skin, this is a chronic scarring process.

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.

Onychodystrophy due to porokeratosis of Mibelli: a rare association

Porokeratosis is a specific keratinization disorder that manifests clinically as well-demarcated annular or linear keratotic plaques of various sizes and forms and with distinguished histology showing cornoid lamella, which is a column of closely packed parakeratotic cells extending through the stratum corneum. Nail changes secondary to porokeratotic lesions involving digits are quite uncommon and rarely reported in the porokeratosis of Mibelli (PM) subtype. Here we report the case of a young girl with a PM lesion over the hand along with nail dystrophy of the involved digit.