Clinical and histological aspect of erythema dyschromicum perstans in Korea: A review of 68 cases

Disorders of Facial Hyperpigmentation

Disorders of hyperpigmentation are common and challenging conditions which can arise due to a myriad of etiologic factors. Many of them can present across skin types but are more common in skin of color individuals with Fitzpatrick skin types III-VI. Facial hyperpigmentation, in particular, can have a significant impact on the quality of life of affected individuals due to its increased visibility. This article provides a comprehensive review of disorders of facial hyperpigmentation including epidemiology, pathogenesis, diagnostic considerations, and treatment approaches for these conditions.

Annular lichenoid diseases

Annular lichenoid diseases encompass a diverse range of pathologies that present as circular, raised, or flat lesions that may vary in size and number. Examples include annular lichenoid dermatitis of youth, annular lichen planus, erythema dyschromicum perstans, erythema multiforme, fixed drug eruption, lichen sclerosus, neonatal lupus, porokeratosis, subacute cutaneous lupus erythematosus, and lichenoid syphilis. Clinical morphology and histopathology can differentiate these entities.

Ashy Dermatosis and Lichen Planus Pigmentosus: The Histopathological Differences

Background

Ashy dermatosis (AD) and lichen planus pigmentosus (LPP) are both acquired macular pigmentation of uncertain aetiology. Despite the controversy surrounding their entities, recent global consensus has concluded that they are 2 different diseases with distinct clinical presentations. Nevertheless, there are limited data on their histopathological comparisons.

Objective

To evaluate the differences in histopathological findings between AD and LPP.

Methods

Electronic records and photographs of patients with the diagnosis of AD or LPP from January 2008 to December 2018 were retrospectively reviewed by a dermatologist. Patients were then classified into groups with AD and LPP, based on the clinical descriptions from the recent consensus. Those with history/clinical presentations suggestive of other causes of macular pigmentation were excluded. The histopathological diagnosis of AD and LPP was then reevaluated by a blinded dermatopathologist.

Results

One hundred and twenty-four patients with acquired macular pigmentation were identified; 24 were excluded due to clinical history or photographs being inconsistent with AD or LPP. Of the remaining 100 patients, 71 had clinical findings consistent with LPP while 29 had AD. The prevalence of epidermal hyperkeratosis was significantly higher in LPP when compared to AD (33.8% vs. 0%, p < 0.001), as well as epidermal hypergranulosis (35.2% vs. 0%, p < 0.001), lichenoid dermatitis (49.3% vs. 7.1%, p < 0.001), perifollicular infiltration (47.9% vs.10.3%, p < 0.001), and perifollicular fibrosis (35.2% vs. 10.3%, p=0.01). In addition, the degree of pigmentary incontinence was more severe in LPP (21.1% vs. 3.5%, p=0.015). For AD, vacuolization of the epidermal basal cell layer was more common (96.4% vs. 77.5%, p=0.02).

Conclusions

Although most cases of AD and LPP can be diagnosed clinically, in doubtful cases, histopathological findings of lichenoid dermatitis, epidermal hyperkeratosis/hypergranulosis, and moderate to severe pigmentary incontinence can help distinguish LPP from AD.

Pembrolizumab resolves adult ashy dermatosis developing in patients with squamous cell carcinoma of the lung

Ashy dermatosis is a rare cutaneous disorder of unknown etiology. We describe a case of adult ashy dermatosis developing in a patient with squamous cell carcinoma of the lung, which was resolved by the administration of pembrolizumab in parallel with multiple vitiligo. Interestingly, immunohistochemical staining revealed that lesional skin of the ashy dermatosis contained cytotoxic T cells and programmed death ligand 1 expressing cells. To our knowledge, this is the first case of adult ashy dermatosis resolved by pembrolizumab.

Erythema dyschromicum perstans: A case report and systematic review of histologic presentation and treatment

Objective

Erythema dyschromicum perstans (EDP) can be difficult to diagnose and treat; therefore, we reviewed the literature to assess whether histology can be used to differentiate lichen planus pigmentosus (LPP) from EDP and determine which treatments are the most effective for EDP. We also present a case of a patient who was treated successfully with narrow-band ultraviolet B (NB-UVB).

Methods

A systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses was conducted up to July 2017 using four databases.

Results

Histologic analyses from the literature reveal a significant percentage of melanophages, lymphocytic infiltrates, and basal vacuolar degeneration in EDP, and a significant histologic overlap with LPP. The review of the literature on treatment outcomes showed that NB-UVB and tacrolimus were effective with minimal side effects. Clofazimine was effective, but demonstrated significant-to-intolerable side effects. Griseofulvin, isotretinoin, and dapsone provided unsatisfactory results as lesions recurred after discontinuation. Lasers were largely ineffective and may cause postinflammatory hyperpigmentation and fibrosis.

Conclusion

A diagnosis of EDP should not be based on histologic findings alone. Clinical history, morphology, and distribution should be used to differentiate EDP and LPP. NB-UVB and tacrolimus are promising treatments for EDP with minimal side effects. This is the first report to our knowledge of sustained resolution of EDP after treatment with NB-UVB at long-term follow-up of 4 years. Larger studies are needed to confirm these findings.

Erythema Dyschromicum Perstans in an 8-Year-Old Indian Child

We report an 8-year-old East Indian boy with erythema dyschromicum perstans. The condition has very rarely been reported in prepubertal Indian children. A perusal of the literature revealed but two cases, to which we add another one. Recognition of erythema dyschromicum perstans in prepubertal Indian children is important for proper diagnosis and to prevent unnecessary investigations.

Pigmented Deposits in the Skin

Pigmented deposits can occur in the skin due to many and varied causes. Some of them are systemic conditions accompanied by involvement of internal organs. Others have serious prognostic implications, and early diagnosis can help in the correct and adequate management of the diseases. In addition, some of them are quite innocuous and the correct diagnosis avoids unnecessary treatments. In this article, we review the morphologic features of some of the most common and some of the less usual pigmented deposits in skin other than tattoos.

Lichenoid and interface dermatoses

The terms 'lichenoid' and 'interface' dermatitis are often used interchangeably to describe an inflammatory pattern characterized histologically by damage to the basal keratinocytes in the epidermis. The mechanism of cell damage of such cells is now best understood as apoptosis, or programmed cell death. This inflammatory pattern of dermatoses, is also accompanied frequently by a band of lymphocytes and histiocytes in the superficial dermis, that often obscures the dermal-epidermal junction, hence the term 'lichenoid'. A discussion of the more common lichenoid/interface dermatitides encountered in the routine clinical practice encompasses the following entities: lichen planus, lupus erythematosus, dermatomyositis, erythema multiforme, graft versus host disease, fixed drug reactions, and multiple others.

Erythema Dyschromicum Perstans: Identical to Ashy Dermatosis or Not?

Erythema dyschromicum perstans (EDP) and ashy dermatosis (AD) are pigmentary disorders of unknown etiology. EDP is usually considered to be identical to AD; however, a new clinical classification for EDP was proposed in the recent literature. Herein, we report a typical case of EDP observed in an African-American man. Interestingly, the late skin lesions in this case fit the criteria of AD as well. While there appear to be a few clinical cases that can be diagnosed as both EDP and AD based on the clinical course, the preponderance of the evidence in the published reports of EDP and AD and the clinical findings reported here strongly suggest that they are two distinct entities in terms of the extent of the inflammation, albeit on the same spectrum of pigment disorders.