Differentiation of pityriasis rubra pilaris from plaque psoriasis by dermoscopy

Pityriasis Rubra Pilaris: An Updated Review of Clinical Presentation, Etiopathogenesis, and Treatment Options

Pityriasis rubra pilaris (PRP) is a rare papulosquamous reaction pattern with a significant impact on quality of life. Type I PRP is the most common PRP variant, presenting as erythematous papules emerging in a follicular distribution and later coalescing into plaques with characteristic islands of sparing; histologically, an alternating pattern of orthokeratosis and parakeratosis is considered the hallmark of PRP (checkerboard hyperkeratosis). Other PRP variants (types II-V) differ in their age of onset and clinical presentation. Type VI PRP is a rare PRP subtype associated with human immunodeficiency virus infection and is occasionally associated with diseases of the follicular occlusion tetrad. Caspase recruitment domain family, member 14 (CARD14)-associated papulosquamous eruption and facial discoid dermatitis are newly described disease states that have an important clinical overlap with PRP, creating shared conundrums with respect to diagnosis and treatment. The etiology inciting PRP often remains uncertain; PRP has been suggested to be associated with infection, malignancy, or drug/vaccine administration in some cases, although these are based on case reports and causality has not been established. Type V PRP is often due to inborn CARD14 mutations. Furthermore, recent literature has identified interleukin-23/T-helper-17 cell axis dysregulation to be a major mediator of PRP pathogenesis, paving the way for mechanism-directed therapy. At present, high-dose isotretinoin, ixekizumab, and secukinumab are systemic agents supported by single-arm prospective studies; numerous other agents have also been trialed for PRP, with variable success rates. Here, we discuss updates on clinical manifestations, present new insights into etiopathogenesis, and offer a survey of recently described therapeutic options.

Misdiagnosed Pityriasis Rubra Pilaris Successfully Managed With Isotretinoin: A Case Series

Being a rare inflammatory, hyperproliferative dermatosis, diagnosing pityriasis rubra pilaris (PRP) can be a challenge to many clinicians. Our case reports aim to demonstrate that PRP is frequently diagnosed and managed as atopic dermatitis (AD) and that distinguishing features on dermoscopy, and biopsy can help diagnose this rare disease. The study also aims to show that PRP can be successfully treated with Isotretinoin. Our case series aims to describe two cases of PRP, initially diagnosed as AD and managed with topical corticosteroids. Being the first case series in the literature to describe the incidences of diagnosing PRP as AD portrays the significance of utilizing dermoscopy and biopsy as tools to confirm this diagnosis for appropriate management. Although PRP is a rare diagnosis, dermoscopy and biopsy can help confirm the disease. Management with isotretinoin will most likely have successful outcomes in those patients.

Dermoscopy of Gottron's papules and other inflammatory dermatoses involving the dorsa of the hands

BACKGROUND

Several inflammatory dermatoses, including dermatomyositis (DM), may present as erythematous papules or plaques on the dorsal aspects of the hands over the joints. Limited skin involvement in these entities may pose a diagnostic challenge. (Video)dermoscopy is being utilized more frequently to aid in differential diagnosis of inflammatory skin conditions.

OBJECTIVE

To describe the dermoscopic findings in Gottron's papules and compare with dermoscopic features of other dermatoses involving the dorsal aspects of the hands.

METHODS

Videodermoscopic images from patients presenting with erythematous papules or plaques on the dorsal surface of the hands were retrospectively analyzed for the presence of standardized dermoscopic parameters.

RESULTS

Dermoscopic images from patients with DM (n=12), psoriasis (n=19), chronic dermatitis (n=16), mycosis fungoides (n=7), lichen planus (n=5) and pityriasis rubra pilaris (n=3) were included. Gottron's papules were characterized by pleomorphic vessels (dotted vessels accompanied by thick or thin linear vessels with branches or linear curved vessels) in 66.7% of cases, arranged in unspecified pattern (91.7%), and accompanied by white or pink structureless areas (75.0%). Psoriatic plaques were characterized by dotted vessels arranged in a uniform pattern (94.7%). Vessels arranged in a ring pattern were nearly exclusively observed in psoriasis, while yellow structureless areas and erosions were more frequently present in chronic dermatitis. White lines, corresponding to Wickham striae, were specific for lichen planus.

CONCLUSIONS

Videodermoscopy might be of value in differentiating Gottron's papules from other dermatoses involving dorsa of the hands.

The significance of dermoscopy and trichoscopy in differentiation of erythroderma due to various dermatological disorders

BACKGROUND

The diagnosis of a patient with erythroderma may be difficult and sometimes pose a challenge for both dermatologist and pathologist. The role of dermoscopy in this area seems to be poorly investigated. There are only a few reports, with limited number of patients, describing dermoscopic features in erythroderma of various origins. To the best of our knowledge, none of the previous studies had included trichoscopic examination.

OBJECTIVES

Analysis of dermoscopic and trichoscopic patterns in series of patients with erythroderma.

METHODS

We retrospectively analysed 28 adult patients who presented with erythroderma between May 2016 and August 2020. Demographic data, disease course and duration, previous treatment, as well as dermoscopic and trichoscopic features were analysed.

RESULTS

There were 9 patients (32.1%) with the diagnosis of mycosis fungoides, 8 patients (28.5%) with atopic dermatitis, 3 patients (10.5%) with Sézary syndrome and 3 patients (10.5%) with pityriasis rubra pilaris. The others were diagnosed with allergic eczema (n = 1; 3.6%), dermatomyositis sine myositis (n = 1; 3.6%), psoriasis (n = 1; 3.6%), actinic reticuloid (n = 1; 3.6%) and crusted scabies (n = 1; 3.6%). Characteristic dermoscopic/trichoscopic patterns have been observed in erythroderma due to crusted scabies, psoriasis, dermatomyositis sine myositis, Sézary syndrome and pityriasis rubra pilaris. Differentiation of mycosis fungoides and long-standing atopic dermatitis based on dermoscopy is difficult, as the overlap of vessel morphology, background colour and scale colour exists. Similarly, differentiation between AD and AE based on dermoscopy/trichoscopy seems to be impossible, and clinical background is crucial.

CONCLUSION

Dermoscopy and trichoscopy seem to provide additional clues in the assessment of erythrodermic patient. Depending on the underlying cause, trichoscopy or dermoscopy may be more useful.