Mimickers of classic acantholytic diseases

Galli-Galli Disease: A Comprehensive Literature Review

Galli-Galli disease (GGD) is a rare genodermatosis that exhibits autosomal dominant inheritance with variable penetrance. GGD typically manifests with erythematous macules, papules, and reticulate hyperpigmentation in flexural areas. A distinct atypical variant exists, which features brown macules predominantly on the trunk, lower limbs, and extremities, with a notable absence of the hallmark reticulated hyperpigmentation in flexural areas. This review includes a detailed literature search and examines cases since GGD's first description in 1982. It aims to synthesize the current knowledge on GGD, covering its etiology, clinical presentation, histopathology, diagnosis, and treatment. A significant aspect of this review is the exploration of the genetic, histopathological, and clinical parallels between GGD and Dowling-Degos disease (DDD), which is another rare autosomal dominant genodermatosis, particularly focusing on their shared mutations in the KRT5 and POGLUT1 genes. This supports the hypothesis that GGD and DDD may be different phenotypic expressions of the same pathological condition, although they have traditionally been recognized as separate entities, with suprabasal acantholysis being a distinctive feature of GGD. Lastly, this review discusses the existing treatment approaches, underscoring the absence of established guidelines and the limited effectiveness of various treatments.

Diagnostic Pearls of Vulvar Epidermolytic Acanthoma: Case Report

Epidermolytic acanthomas (EA) are uncommon benign tumors clinically presenting as single to multiple papules. Histologically, EA display hyperkeratosis, hypergranulosis, acanthosis, and epidermal degeneration—also known as epidermolytic hyperkeratosis (EH). EA may be misdiagnosed as condyloma both clinically and histopathologically when located on the genitalia. Thus, this diagnosis carries a significant psychological burden and must remain in the differential when initially considering genital warts. We utilize the case of a 62-year old female referred to dermatology for a 5-year history of multiple pruritic and hypopigmented vulvar papules—misdiagnosed as genital warts—to highlight the impact of differentiating EA from genital warts. This patient was initially misdiagnosed with common genital warts at her gynecologist’s office and treated unsuccessfully for years. A shave biopsy was performed and histology revealed EH, consistent with EA.

Darier and Hailey-Hailey disease: update 2021

The autosomal-dominant genodermatoses Darier disease and Hailey-Hailey disease present special challenges to dermatologists. Despite their similar pathogenesis featuring impaired adhesion of suprabasal keratinocytes as a result of defective ATPases in epidermal calcium channels, the two diseases differ considerably in clinical presentation and therapeutic options. Darier disease is characterized by reddish brown, keratotic papules in seborrheic and intertriginous areas, which may coalesce into extensive lesions. Individuals affected with Hailey-Hailey disease primarily develop intertriginous papulovesicles and small blisters, which often evolve into erythematous plaques with erosions and painful fissures. Quality of life is significantly reduced because of complaints (itch, burning sensation, pain), body malodor and chronicity. Therapeutic options remain limited. Antiseptics and intermittent topical corticosteroids are a cornerstone of therapy, and systemic anti-infective treatment is often required in cases of superinfection. Ablative surgical interventions such as dermabrasion and CO₂ laser surgery can lead to long-term remissions in intertriginous Hailey-Hailey disease, while temporary relief may also be achieved by intralesional injections of botulinum toxin. Of the systemic medications available for Darier disease, acitretin, which is approved for this purpose, has the best supporting evidence. The efficacy of immunosuppressants and immune modulators is inconsistent. Low-dose naltrexone produces more satisfactory results in Hailey-Hailey than Darier disease. The present CME article summarizes current knowledge of the two dermatoses, taking recent developments into account.

Histopathology of Pemphigus Vulgaris Revisited

ABSTRACT

Pemphigus vulgaris (PV) is a severe, potentially life-threatening autoimmune blistering disease, which is common in India. Although there is abundant literature on clinical and immunologic features, comprehensive studies on its histopathology are lacking. The aim of this study was to describe the histopathologic and immunofluorescence features as well as discuss various diagnostic pitfalls of PV. Histopathologic and immunofluorescence (DIF/IIF) findings were reviewed for 169 biopsies from 2007 to 2017 (11 years). The 169 samples included 152 skin, 16 oral mucosal, and 1 corneal biopsy. Maximum prevalence was noted in the fifth decade (57%) with a slight male preponderance. Vesicles were seen in 149 cases (88%), the level of which was suprabasal in 91(61%) and both suprabasal and intraepidermal in 50 cases (33.5%). Acantholytic cells were present in 142 cases (95%). Acantholytic keratinocytes showed rounded and polygonal acantholysis. 86 (51%) cases showed evidence of regeneration. Adnexal involvement was seen in 92 cases, commonest in the hair follicles. Unusual histologic findings included: intraepidermal bulla, absence of dermal inflammation, free floating hair shafts, multinucleated epithelial cells, eosinophil predominance; all of which are discussed. DIF was performed in 166 cases, of which 163 were positive (98%), and IgG was the commonest immunoreactant (96%). IIF was performed in 11 cases, of which 9 cases were positive for Dsg3. Although the diagnosis of PV rests on combined clinical, histologic, and IF features, histopathology as the sole means is also a powerful tool. It is important to be aware of the diagnostic pitfalls to optimize its utility.

Hailey-Hailey Disease: An Update Review with a Focus on Treatment Data

Hailey-Hailey disease is a rare blistering dermatosis first described in 1939 by the brothers Howard and Hugh Hailey. Its incidence is estimated at 1/50,000. The inheritance is autosomal dominant with complete penetrance, but a variable expressivity in affected family members. Clinically, Hailey-Hailey disease presents between the third and fourth decade as flaccid vesicles and blisters on erythematous skin, giving rise to erosions, fissures, and vegetations. Maceration and superinfections are frequent. The lesions are typically distributed symmetrically within intertriginous regions such as the retroauricular folds, lateral aspects of the neck, axillae, umbilicus, inguinal, and perianal regions. The disease is characterized by a chronic relapsing course with spontaneous remissions and multiple recurrences. Severe disease can be very frustrating and have a major psychological and social impact. Given the dearth of evidence-based guidelines and large clinical trials, the assessment of the efficacy and safety of treatments is difficult. Treatments include topical and systemic agents, and procedural therapy such as lasers and surgery. This review provides a systematic search of the literature with a focus on classical and emerging treatment options for Hailey-Hailey disease.

Classic Findings, Mimickers, and Distinguishing Features in Primary Blistering Skin Disease

Context.—

Blistering diseases comprise a large group of clinically polymorphic and sometimes devastating diseases. During the past few decades, we have developed an elegant understanding of the broad variety of blistering diseases and the specific histopathologic mechanism of each.

Objective.—

To review examples of the classic findings of specific blistering diseases and emphasize the importance of considering unrelated conditions that can mimic the classic finding.

Data Sources.—

This article combines data from expert review, the medical literature, and dermatology and pathology texts.

Conclusions.—

We have chosen several common examples of classic blistering diseases that are mimicked by other cutaneous conditions to highlight the basic findings in blistering conditions and the importance of clinician-to-pathologist communication.

Dermoscopic and reflectance confocal microscopic presentation of Hailey-Hailey disease: A case series

BACKGROUND/PURPOSE

Hailey-Hailey disease is a rare inherited acantholytic skin disorder characterized by heterogeneous clinical presentation. Its differential diagnosis might be wide, including other genodermatoses, inflammatory, and infectious skin diseases. Although histopathology remains as diagnostic gold standard, noninvasive techniques such as dermoscopy and reflectance confocal microscopy may assist clinical examination. Herein, we aim to further characterize the dermoscopic and reflectance confocal microscopic presentation of Hailey-Hailey disease with histologic correlation.

METHODS

Eight patients with Hailey-Hailey disease were consecutively recruited. All patients were examined using dermoscopy and reflectance confocal microscopy.

RESULTS

In all cases, dermoscopy enabled the visualization of polymorphous vessels, including glomerular and linear-looped vessels, within a pink-whitish background. Reflectance confocal microscopy revealed wide suprabasilar partial acantholysis and clefting, crusts, dilated papillae with tortuous vessels, and inflammatory cells. Dyskeratosis, uplocated papillae, and adnexal sparing were also observed.

CONCLUSION

Although definite diagnosis was obtained by histopathology in all cases, dermoscopy and reflectance confocal microscopy allowed the identification of common features (even in cases with dissimilar clinical presentation) that may support an early diagnosis of Hailey-Hailey disease, and its differentiation from other more frequent skin disorders.