Linear porokeratosis: successful treatment with diamond fraise dermabrasion

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.

Bilateral Linear Porokeratosis Treated With Topical Lovastatin 2% Monotherapy

Linear porokeratosis is a rare skin disorder that presents along dermatomal or Blashko lines. While the mechanism of linear porokeratosis formation is unknown, both disrupted cholesterol synthesis and mevalonate accumulation have been proposed as possible theories. There is a small chance of transforming into cutaneous malignancies, most commonly squamous cell carcinomas. The patient is a 61-year-old male with an unusual presentation of bilateral linear porokeratosis. His condition provided a unique opportunity to compare the efficacy of topical treatments in a single individual. A previous trial had successfully cleared the porokeratosis plaques with topical cholesterol 2%/lovastatin 2% on the patient's right arm. After a 12-week trial of topical lovastatin 2% monotherapy on the left arm, our current study demonstrated a comparable reduction of porokeratosis lesions. In our PubMed search, there has been a single reported case of disseminated superficial actinic porokeratosis successfully treated with topical lovastatin 2% monotherapy, but there have not been any reported cases of linear porokeratosis treated with this therapy. While topical lovastatin monotherapy for porokeratosis subvariants requires further studies, this case demonstrates similar efficacy of treating linear porokeratosis with topical lovastatin compared to cholesterol/lovastatin dual therapy. These findings support the theory of mevalonate accumulation as a more likely cause of linear porokeratosis compared to disruption of cholesterol synthesis.

[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.

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.

Linear porokeratosis presenting as erosions in the newborn period

The classic appearance of porokeratosis is characterized by a hyperkeratotic annular rim that expands peripherally, leaving an atrophic center. Linear porokeratosis is a variant with collections of such lesions arranged in a linear fashion, usually corresponding to a dermatome or Blaschko's lines. Ulcerations have rarely been reported in patients with porokeratosis. We report an unusual case of linear porokeratosis at birth, with erosions and ulcerations of the face and lower extremity, that eluded diagnosis for nearly a year. Porokeratosis should be considered in the differential diagnosis of erosions in the newborn period.

Treatment of porokeratosis of Mibelli with CO2 laser vaporization versus surgical excision with split-thickness skin graft. A comparison

BACKGROUND

Porokeratosis of Mibelli has been treated with many topical surgical modalities in the past, including cold steel surgical excision and CO2 laser excision. We report a patient with an 8 x 10 cm2 plaque of porokeratosis on the dorsum of his hand, fingers, and web spaces.

OBJECTIVE

To compare the treatment results of CO2 laser vaporization versus cold steel surgical excision with split-thickness skin graft placement.

METHOD

The portions of the lesion overlying the metacarpophalangeal joints, fingers, and web spaces were treated with CO2 laser vaporization. The remainder of the lesion covering the dorsum of the hand was excised with cold steel, followed by placement of a split-thickness skin graft over that area.

RESULTS

The portion of the porokeratosis lesion treated with CO2 vaporization healed with results cosmetically and functionally superior to the grafted area.

CONCLUSION

Carbon dioxide laser vaporization, a more superficial treatment modality than CO2 laser excision, should be the preferred treatment modality for porokeratosis lesions.