OBJECTIVE: Recent literature highlights the potential of biologics in the management of inherited disorders of keratinisation. In this study, we conducted a systematic review of existing literature on treatment outcomes of inherited keratinisation disorders treated with biologics.
METHODS: Eligible records were retrieved through searches of the electronic databases MEDLINE, Embase, PubMed and Scopus. Databases were searched from inception to July 2023 for eligible records. A snowballing method was employed to search the references of the retrieved records for the identification of potentially relevant articles.
RESULTS: One hundred and four eligible studies consisting of a total of 166 patients with an inherited disorder of keratinisation were included. Patients had a median age of 19 years (range: 0.5 to 70 years). The most common disorders were Netherton syndrome (n = 63; 38%), autosomal recessive congenital ichthyoses (n = 27; 16%), CARD14-associated papulosquamous eruptions (n = 17; 10%) and familial pityriasis rubra pilaris (PRP) (n = 15; 9%).Of the 207 times biologics were employed, the three most frequently employed biologics were secukinumab (n = 47; 23%), dupilumab (n = 44; 21%) and ustekinumab (n = 37; 18%). Complete remission was observed in 10 (5%) instances, partial remission in 129 (62%), no or limited response to biologic therapy in 68 (32%) cases, and results are still pending in one case. A total of 33 adverse events were reported.
CONCLUSIONS: Whilst biologics may be considered in cases of inherited keratinisation disorders recalcitrant to standard therapy, definitive conclusions are prohibited by the low-level of evidence and substantial heterogeneity in methodology across the included studies. Establishment of consensus definitions, and randomised clinical trials may help ascertain the efficacy and safety of biologic therapy in this context and establish the best agent and dosing protocol for each disorder.

Papillon-Lefevre syndrome (PLS) manifests as an autosomal recessive disorder caused by a mutation in the cathepsin C (CTSC) gene. This genetic alteration results in palmoplantar hyperkeratosis, rapid onset of periodontitis, and premature shedding of both primary and permanent teeth. The major etiological factor responsible for the development of this disorder appears to be variations in the CTSC gene, which is responsible for the production of the cathepsin C enzyme in the body. The multifactorial aetiology of the syndrome is influenced by immunologic, genetic, or microbial factors. This case report presents a clinical picture of a 21-year-old Indian male patient with oligodontia and mobile teeth accompanied by palmoplantar keratosis and a history of recurrent infection. The detailed family history of the patient revealed genetic relevance with PLS. This article will discuss in detail the diagnosis, evaluation and treatment modalities involved in the management of the case.

Familial dyskeratotic comedones (FDC) is an autosomal dominant inherited skin disorder characterized by generalized multiple discrete comedone-like hyperkeratotic papules. The disease demonstrates a distinct histopathologic feature of dyskeratosis of the crater-like invaginated epidermis or follicle-like structures with or without acantholysis. Despite its asymptomatic and benign course, the condition is refractory to treatment. Herein, we report a case of a 54-year-old female presenting with progressively developed generalized multiple hyperkeratotic papules with central keratin plugs on the trunk and extremities for 20 years. A definite diagnosis was made by clinical manifestations and histopathological examination. The lesions were slightly improved after 3 months of topical retinoids and urea cream treatments. Besides, we first describe dermoscopic findings of FDC and reviewed 21 previously reported FDC cases from 11 families in the literature.

BACKGROUND: Nevus comedonicus (NC) is a rare cutaneous disorder thought to be caused by hamartomatous pilosebaceous tissue proliferation that was first described in 1895. Clinically NC appears as a group of elevated follicular openings often linearly arrayed, giving the appearance of comedones. NC usually manifests at birth but can also present later during adolescence and rarely in adulthood.
METHODS: A 21-year-old medically healthy single male presented with right-sided chest black papules in comedo distribution with areas of superficial ulcerations and suppurations in periareolar distribution since the age of 16. Histopathological examination showed dilated follicular ostia filled with keratin plug, devoid of the hair shaft, and lined by stratified squamous epithelium with compact hyperkeratosis, focal parakeratosis, and patchy atrophy and acanthosis.
UNASSIGNED: Nevus comedonicus often responds effectively to conservative treatment, however some cases need surgery intervention. The patient failed conservative medical and topical treatment, and he was treated by surgical-wide local excision and primary closure of the affected skin with free nipple grafting.
CONCLUSIONS: Nevus comedonicus (NC) is a rare cutaneous pathology secondary to pilosebaceous apparatus developmental defect that usually manifests at birth and can affect any area of skin; they typically manifest as black papules in comedo distribution. They can present as an isolated cutaneous pathology or as a component of nevus comedonicus syndrome. Different therapeutic approaches were described, including topical retinoids, keratolytic agents, oral retinoids, antibiotic therapy, manual extraction of comedos, dermabrasion, and surgical resection of the lesion.

UNASSIGNED: Hyperkeratosis of the nipple and areola (HNA) is a rare skin disease with unknown etiology. Some patients are misdiagnosed or never diagnosed, especially during the early stage of this disease. In addition, the mechanism involved in the development of HNA is still unknown, and genomic alterations have not been reported anywhere.
UNASSIGNED: A 26-year-old female suffered gradual bilateral areola thickening and enlargement, with accompanying intense itching, and was diagnosed with HNA at the First Affiliated Hospital of Chongqing Medical University. No obvious abnormalities were found in laboratory test examinations such as hormone testing for estrogen, progesterone, or prolactin. Typical papillomatous skin with orthokeratotic hyperkeratosis and numerous infiltrating lymphocytes was detected through a histopathological examination. The results from RNA-sequencing showed that the molecular expression between HNA and a normal nipple and areola (NNA) was obviously different. No significant difference was found in the bilateral lesions. In addition, immune-related cell signaling pathways were overactivated in HNA compared to the control HNA.
UNASSIGNED: The typical symptoms, clinical features, and histopathological alterations presented in this case lead to a profound understanding of HNA, which can avoid the misdiagnosis and missed diagnosis of this disease at an early stage. The dysfunction of the local immune system, which was demonstrated by pathological examination and genomic analysis, suggests that anti-autoimmune therapy, such as steroid medication, may be an effective treatment for HNA at an early stage.

Granular parakeratosis (GP) is a distinctive acquired keratotic dermatosis that is usually presented with brownish-red hyperkeratotic papules and plaques in the intertriginous areas. Follicular involvement in GP could be either extending lesions from interfollicular epithelium or originating primarily from the follicular epithelium. The latter was named follicular GP and is considered an extremely rare condition. To our knowledge, there has been one reported case so far in the literature. We herein report the second case of follicular GP in a 52-year-old Thai man presenting with multiple tiny filiform hyperkeratotic papules on his face 2 weeks after using anti-melasma cream. We also propose a classification of GP based on its distinct clinical manifestations and histopathological findings.

Plasmoacanthoma (PA) is a verrucous tumor predominantly developing on periorificial areas, which has been considered as an unusual subtype of plasmacytosis circumorificialis. Because of its rarity and clinical resemblance to several verrucous dermatological disorders, accurate diagnosis of PA is quite challenging. Herein, we present an extremely unusual case of PA which arose on both sides of the nasal canthus and was successfully treated with intralesional corticosteroid injections. To elucidate clinicopathological features of this condition, a literature review was also attempted. A 78-year-old woman visited us with a 2-year history of eruptions affecting both sides of the nasal canthus. At a local clinic, the diagnosis and treatment had been unsuccessful due to non-specific histological findings, leading to the referral to our institute. On physical examination, verrucous and lobulated reddish plaques were observed. In histology, psoriasiform epidermal change and dense plasma cell infiltration in the dermis were detected. The diagnosis of PA was made. After 5-monthly intralesional triamcinolone acetonide injections, the lesions became hardly noticeable with no evidence of recurrence. A literature review found five PA cases. PA predominantly arose on the periorificial area, mostly in or around the mouth, except one case which developed on the extra-oral or perioral area. Intralesional corticosteroid injection has been preferably performed, which frequently achieved successful remission. Chronic inflammation has been reported as a preceding condition. Abundance of plasma cells in the lacrimal glands and conjunctiva, together with pre-existing allergic conjunctivitis and habitual scratching, might have contributed to PA development in our case. Histopathological detection of psoriasiform epidermal change and dense dermal plasma cell infiltration is indispensable for the diagnosis of PA. For accurate diagnosis, optimization of treatment, and further accumulation of extra-oral/perioral PA cases, a skin biopsy needs to be proactively performed on verrucous lesions on relatively unfamiliar orifice sites.

Because of technical limitations, an impact of machine milking on the teat tissue cannot be avoided. The continuance of this impact during and after milking depends on a variety of factors related to the physiological regulation of milk ejection, as well as the different production systems and milking machine settings. Milking machine settings aim to achieve a high milking performance, that is, short machine-on time at a maximum of milk harvest. However, a high milking performance level is often related to an impact on the teat tissue caused by vacuum or liner compression that can lead to pathological dimensions of congestion of the tissue or hyperkeratosis as a long-term effect. Toward the end of milking a decrease of milk flow rate causes a raise of mouthpiece and teat end vacuum levels and hence an increase of the impact on the teat tissue and the risk of tissue damage. The mechanical stress by the milking machine activates a cascade of cellular mechanisms that lead to an excessive keratin growth and thickening of the keratin layer. Consequently, a complete closure of the teat canal is disabled and the risk of bacterial invasion and intramammary infection increases. Another consequence of high vacuum impact is fluid accumulation and congestion in the tissue of teat tip and teat basis because of an obstruction in venous return. The present review paper provides an overview of the available scientific information to describe the interaction between different levels and types of system vacuum, mouthpiece chamber vacuum, teat end (claw) vacuum, liner pressure, and the risk of short-term and long-term impacts on the teat tissue.

Angiokeratoma is a benign cutaneous lesion of capillaries. It is characterized by large dilated blood vessels in the superficial dermis and hyperkeratosis of extremities. It is mostly seen in generalized form affecting the extremity of the body, but we report this case of solitary angiokeratoma of the tongue which is a very rare type.

Verrucous carcinoma of the esophagus is a variant of a squamous cell cancer. Our case is a 78-year-old male patient comes in with the dysphagia and weight loss, and on endoscopy (EGD) he is found to have an irregular intraluminal mass at the distal esophagus. With the deep EGD assisted biopsy, diagnosis of the verrucous carcinoma is made. Due to multiple co morbidities and possible infiltration to the pericardium, patient is taken for the esophageal stent placement and is being referred for the chemo-radiation treatment. The diagnosis can be very difficult to make with the superficial biopsies due to very non specific histological changes and requires very high clinical suspicion and deep mucosal biopsies are required for accurate diagnosis of the tumor. Chronic and local disease process is the main risk factor for the development of the verrucous carcinoma of the esophagus. Surgery is the treatment of the choice for the early stage tumor and advanced cases are treated with the palliation and possibly chemo- radiation. The prognosis is usually guarded and needs long term follow up.