Persistent Cutaneous Lesions of Darier Disease and Second-Hit Somatic Variants in ATP2A2 Gene.

Importance: Darier disease (DD) is a rare genetic skin disorder caused by heterozygous variants in the ATP2A2 gene. Clinical manifestations include recurrent hyperkeratotic papules and plaques that occur mainly in seborrheic areas. Although some of the lesions wax and wane in response to environmental factors, others are severe and respond poorly to therapy. Objective: To investigate the molecular mechanism underlying the persistency of skin lesions in DD. Design, Setting, and Participants: In this case series, DNA was extracted from unaffected skin, transient and persistent lesional skin, and blood from 9 patients with DD. Genetic analysis was used using paired-whole exome sequencing of affected skin and blood or by deep sequencing of ATP2A2 of affected skin. Chromosomal microarray analysis was used to reveal copy number variants and loss of heterozygosity. All variants were validated by Sanger sequencing or restriction fragment length polymorphism. Interventions or Exposures: Paired whole-exome sequencing and deep sequencing of ATP2A2 gene from blood and skin samples isolated from persistent, transient lesions and unaffected skin in patients with DD. Main Outcomes and Measures: Germline and somatic genomic characteristics of persistent and transient cutaneous lesions in DD. Results: Of 9 patients with DD, all had heterozygous pathogenic germline variants in the ATP2A2 gene, 6 were female. Participant age ranged from 40 to 69 years on enrollment. All 11 persistent skin lesions were associated with second-hit somatic variants in the ATP2A2 gene. The somatic variants were classified as highly deleterious via combined annotation-dependent depletion (CADD) scores or affect splicing, and 3 of them had been previously described in patients with DD and acrokeratosis verruciformis of Hopf. Second-hit variants in the ATP2A2 gene were not identified in the transient lesions (n = 2) or the normal skin (n = 2). Conclusions and Relevance: In this study, persistent DD lesions were associated with the presence of second-hit somatic variants in the ATP2A2 gene. Identification of these second-hit variants offers valuable insight into the underlying mechanisms that contribute to the lasting nature of persistent DD lesions.

Clinicopathologic and trichoscopic features of keratosis follicularis spinulosa decalvans: A case series study.

Keratosis follicularis spinulosa decalvans (KFSD) is a rare X-linked hereditary disorder characterized by the triad of follicular hyperkeratosis-photophobia-alopecia. The clinical heterogeneity makes the diagnosis difficult. To investigate the clinicopathologic and trichoscopic features of KFSD and to further clarify the essential requisites for the diagnosis, we conducted a retrospective study of patients with KFSD. The clinical information, histologic features, and trichoscopic findings were evaluated. Eight patients were from seven separate families. Two females were mother and daughter from the same family and the other six patients were male and represented sporadic cases. The average age of onset of alopecia was 21.25 years. Involvement of the scalp hairs leading to progressive scarring alopecia on the midline of the scalp with variable degrees of inflammation was the pathognomonic feature. It typically began after puberty. Vellus hair-associated follicular hyperkeratosis affected all of the patients. However, photophobia was not a constant feature. Histopathologic examination revealed disorders of the hair follicle with an acute-chronic inflammatory response. Follicular changes including fused infundibulum, the protrusion of the outer root sheath into the follicular canal, and a dilatation of the follicles at the isthmus level caused by the occlusion of keratin were observed. The trichoscopic features included perifollicular scaling, tufted hairs, and loss of follicular openings. In conclusion, terminal hair involvement, either scalp hairs, eyebrows, or eyelashes, and the hyperkeratosis of the follicle of vellus hairs is the diagnostic basis of KFSD. We hypothesize that follicular changes in histopathology are the primary event that trigger variable inflammation and further follicular destruction.

Kyrle disease: a case report and literature review.

BACKGROUND: Perforating dermatoses are heterogeneous skin disorders characterized by transepidermal elimination of dermal tissue components. Acquired perforating dermatoses can be divided into four types, according to the eliminated dermal materials: Kyrle disease, perforating reactive collagenosis, elastosis perforans serpiginosa, and perforating folliculitis. They characterize adult patients with coexisting systemic diseases, regardless of the dermal materials eliminated. The association between Kyrle disease and renal failure or diabetes mellitus is common. CASE REPORT: We reported the case of Kyrle disease in a patient with chronic kidney disease. A literature review was performed with the aim to highlight the associated comorbidities and point out the role of early and specific treatment of the cutaneous symptoms and manifestations. CONCLUSIONS: Being Kyrle disease a pruritic condition which adversely affects the patient's quality of life, it would be desirable to place greater therapeutic attention on the alleviation of itching and on the correct management of the underlying comorbidity.

Keratosis Pilaris: Treatment Practices of Board-Certified Dermatologists.

Keratosis pilaris (KP) is a chronic disorder of follicular hyperkeratinization and perifollicular erythema with lesions affecting the extensor surfaces of arms, upper legs, and buttocks. While there is some evidence that laser therapies and topical therapies such as lactic acid reduce the follicular papules of KP, support is limited with respect to which topical treatments dermatologists utilize and their perception of efficacy. A 16-question survey was distributed to a random sampling of the ODAC Conference listserv to determine which topical treatments dermatologists utilize the most, the duration of therapy needed with various treatment modalities, and the effectiveness of topical and laser therapy for treating KP. Our study found topical lactic acid is the most used first-line therapy for KP (43.63% of survey respondents), followed by salicylic acid (20.72%). Laser therapy is only utilized by 8.76% of survey respondents, with a lack of insurance coverage and proper equipment limiting its use. KP is often recalcitrant to treatment, and our study demonstrated that over 60% of respondents found recurrence of KP lesions within three months of stopping salicylic acid treatment and OTC moisturizer treatment. The data herein can be used to better utilize the selection of topical and laser therapies for the treatment of KP. J Drugs Dermatol. 2023;22(10):985-989 doi:10.36849/JDD.7534.

Keratosis pilaris: an update and approach to management.

Keratosis pilaris (KP) is a common, hyperkeratotic skin condition characterized by small, folliculocentric papules with variable perifollicular erythema. We provide an updated review on the pathogenesis, clinical manifestations, and management of this common, and often annoying, finding. KP represents a family of follicular disorders, of which KP simplex is by far the most common. Other variants and rare subtypes include keratosis pilaris rubra, erythromelanosis follicularis faciei et colli, and the spectrum of keratosis pilaris atrophicans. Inherited mutations of the FLG gene and ABCA12 gene have been implicated etiologically. KP may be associated with ichthyosis vulgaris and palmar hyperlinearity, but less likely atopic dermatitis. Some potential differential diagnoses for KP include lichen spinulosus, phrynoderma, ichthyosis vulgaris, and trichostasis spinulosa. General cutaneous measures such as hydrating skin, avoiding long baths or showers, and using mild soaps or cleansers should be recommended. Topical keratolytic agents are first-line therapy, followed by topical retinoids and corticosteroids. Recent options include a variety of lasers and microdermabrasion if the patient is refractory to topical therapy.

Keratosis pilaris. / Keratosis pilaris.

Keratosis pilaris, or 'plucked chicken skin', is a very common condition. It is caused by keratin accumulation in the hair follicles. Although mild cases of the condition can be considered to be a normal variant, it can lead to multiple appointments with general practitioners and dermatologists. In rare cases, keratosis pilaris can form part of specific syndromes or be associated with other diseases. The aim of this article is to give an overview of the different variants of keratosis pilaris and discuss the pathogenesis and treatment options.

Heterozygous ATP2A2 missense variant identified in a Shih Tzu with Darier disease.

Darier disease is caused by heterozygous loss of function variants in the ATP2A2 gene encoding the endoplasmic/sarcoplasmic reticulum Ca2+ pump ATP2A2. Defective intracellular calcium signaling in the epidermis results in a loss of desmosomal adhesion and the development of characteristic skin lesions. In this study, we investigated a Shih Tzu that developed erythematous papules on the ventrum and, over time, the dorsal neck and a nodule in the right ear canal with secondary ear infection. Histopathologic examination demonstrated discrete foci of acantholysis affecting suprabasal layers of the epidermis. Whole genome sequencing of the affected dog identified a heterozygous missense variant, p.N809H, affecting an evolutionarily conserved amino acid residue of the ATP2A2 protein. The highly characteristic clinical and histopathologic findings together with a plausible variant in the only known functional candidate gene establish the diagnosis of canine Darier disease in the studied dog and highlight the potential of genetic analyses as complementary diagnostic approach in veterinary medicine.

Anti-desmoglein 1 antibody-positive mother and antibody-negative child with Darier's disease.

We report a mother and an adult son with Darier's disease. The mother, 76 years old and Japanese, had positivity for anti-desmoglein (Dsg)1 antibodies. She had erythema with hyperkeratosis and seborrheic and interstitial blistering. A high level of anti-Dsg1 antibodies was detected in the serum. Histopathological examination showed acantholysis and direct immunofluorescence testing revealed intercellular IgG and C3 deposition of the epidermis. Although she was diagnosed as having pemphigus foliaceus, the skin lesions slightly improved with immunosuppressive therapy. Her son, 47 years old, had similar skin lesions on the seborrheic and interstitial parts, but the anti-Dsg1 antibodies were negative in his serum. Histopathological examination showed acantholysis and dyskeratotic cells. Although Hailey-Hailey disease was first suspected, no mutation in the ATP2C1 was detected in either patient. Trio-exome analysis including the father showed a heterozygous c.2027C>A transition on exon 14 of ATP2A2, causing a replacement at amino acid 676 (p.Ala676Asp) in the mother and son only. The two patients were then diagnosed as having Darier's disease. Exome analysis further showed that a novel heterozygous missense mutation of DSG1 was identified only in the affected mother. Anti-Dsg1 antibody-positive Darier's disease is reported here for the first time. Very rare coexistence of Darier's disease and anti-Dsg1 antibody-positivity might be associated with this novel heterozygous DSG1 mutation. Experimental evidence is required to validate this hypothesis.

Subcellular compartmentalization of STIM1 for the distinction of Darier disease from Hailey-Hailey disease.

BACKGROUND AND OBJECTIVES: Darier disease (DD) and Hailey-Hailey disease (HHD) are rare disorders caused by mutations in the ATPase, Sarcoplasmic/Endoplasmic Reticulum Ca2+ Transporting 2 (ATP2A2) and ATPase Ca2+ Transporting Type 2C, Member 1 (ATP2C1) gene, respectively, which lead to a disturbance of calcium metabolism in keratinocytes. Clinically, this is reflected by an impairment of keratinization. Histologically, acantholysis with variable degrees of dyskeratosis and parakeratosis is observed. Both diseases can usually be differentiated clinically, histopathologically and genetically. However, their routine distinction might be challenging since some patients do not harbor ATP2A2 or ATP2C1 mutations. To solve this diagnostic challenge, we studied the differential expression of two proteins of store-operated calcium entry (SOCE), stromal interaction molecule 1 (STIM1) and calcium release-activated calcium modulator 1 (ORAI1), by immunohistochemistry. PATIENTS AND METHODS: Five individuals with ambiguous diagnostic findings and eight controls with an unambiguous diagnosis were studied clinically, histologically, genetically, and by immunohistochemistry for STIM1 and ORAI1. RESULTS: DD patients consistently showed a cytoplasmic STIM1 expression while patients with HHD revealed a membrane-associated staining pattern. In contrast, ORAI1 did not show a differential expression pattern. CONCLUSIONS: Our data suggest subcellular compartmentalization of STIM1 as novel biomarker for the distinction of the two disorders.