Mona Abdel-Halim

The exact aetiology of pityriasis lichenoides chronica (PLC) remains unknown. While phototherapy is the most investigated therapeutic modality, azithromycin has been used scarcely. The aim of this study is to evaluate the therapeutic efficacy of azithromycin in the treatment of PLC compared to NB-UVB and evaluating the presence of streptococcal infection as a possible etiological factor in PLC patients. The study was designed as a randomised controlled trial. Twenty-four patients with PLC were randomly allocated into either azithromycin (n = 13, standard dose every 10 days) or NB-UVB (n = 11, thrice weekly) groups. End of study (EOS) was either complete clearance of lesions or a maximum of 8 weeks. Therapeutic efficacy was defined as percent reduction in lesions and was calculated for the rash as a whole, erythematous papules alone, and hypopigmented lesions alone and graded into complete, very-good, good, poor or no response. Anti-streptolysin O titre (ASOT), anti-deoxyribonuclease B titre (anti-DNaseB) and throat culture were evaluated at day 0. No significant difference existed between both groups as regards therapeutic efficacy. At EOS, NB-UVB achieved significantly more percent reduction in the extent of hypopigmented lesions and consequently in the rash as a whole (p = 0.001, p = 0.034, respectively). The extent of the rash as a whole was significantly less in the NB-UVB at EOS (p = 0.029, respectively). The effect of NB-UVB on hypopigmented lesions appeared early at week 4 of treatment. Only two patients, one from each group, relapsed during the 3 month follow-up. Evidence of recent streptococcal infection was present in 79% of the cases, mainly in the form of elevated ASOT (94.7%). It was significantly more encountered in young children (< 13 years) (p = 0.03) and was associated with more extent of erythematous papules and consequently with more extent of the rash as a whole (p = 0.05 and p = 0.01, respectively). It did not affect outcome of therapy at EOS. Azithromycin did not show more favorable response in patients with recent streptococcal infection. Therapeutic efficacy of azithromycin is comparable to NB-UVB in treatment of PLC; however, NB-UVB is superior in management of hypopigmented lesions. It is highly suggested that PLC could be a post streptococcal immune mediated disorder.Registration number: ClinicalTrials.gov, NCT03831269.

PURPOSE OF REVIEW: The main purpose of this review is to present newly reported cutaneous manifestations of systemic vasculitis, updates in investigations to verify systemic involvement in cases with cutaneous vasculitis and new therapeutic guidelines. The spectrum of COVID-19-related vasculitis is also covered.

RECENT FINDINGS: Only a few reports highlighted new cutaneous presentations or associations with some systemic vasculitic entities. For example, the association of inflammatory disorders with Takayasu arteritis, the importance of considering Kawasaki disease in febrile children with erythema nodosum, the development of necrotic ulcers on fingers and toes in Behçet's disease and the possible presence of polyarteritis nodosa-like pathological features in vulvar ulcers of Behçet's disease. New attempts to classify cutaneous manifestations of giant cell arteritis (GCA) and antineutrophil cytoplasmic antibody-associated vasculitis (AAV) and the diagnostic investigations for cutaneous vasculitis cases to verify systemic involvement are discussed. Treatment of systemic vasculitis with cutaneous vasculitis should be tailored according to disease status. A plethora of reports in the past 2 years focused on the broad spectrum of COVID-19 vasculitic manifestations.

SUMMARY: Although newly reported cutaneous manifestations of systemic vasculitis are relatively uncommon, the plethora of reports in the past 2 years on COVID-19 vasculitis necessitates the expansion of the classification of vasculitis associated with probable cause to include severe acute respiratory syndrome coronavirus-2 (SARS-Cov-2) vasculitis.

ABSTRACT: Crystalglobulinemia (CG) is a rare disorder characterized by crystallization of monoclonal immunoglobulins in the microcirculation leading to multiorgan vascular thrombosis and ischemic injury. The main cause of CG is multiple myeloma. We report a case of a 52-year-old man who presented with widespread necrotizing plaques and ulcerations. A skin biopsy revealed eosinophilic rectangular-shaped crystals occluding the lumina of blood vessels with no associated features of vasculitis. The crystals were Periodic acid-Schiff stain positive. The findings were diagnostic of CG. Extensive work up lead to the discovery of multiple myeloma. Awareness of CG is important because it may be the first presenting manifestation of an underlying serious hematological malignancy.

BACKGROUND/OBJECTIVES: Pityriasis lichenoides chronica (PLC) lesions are reported to subside with post-inflammatory hypopigmentation (PIH); hence, the most widely perceived nature of hypopigmented macules in PLC is PIH. However, to the best of our knowledge, no studies describing histopathological findings in these lesions are reported in literature. The aim of this study is to evaluate the hypopigmented lesions encountered in PLC patients and to shed light on their histopathological features.

METHODS: A cross-sectional observational study included twenty-one patients with PLC recruited in a period of twelve months. Clinical characteristics of each patient were collected. A skin biopsy from hypopigmented lesions whenever present was taken and assessed with routine haematoxylin and eosin stain.

RESULTS: Seventeen patients (81%) were less than 13 years old. Most patients (85.7%) demonstrated diffuse distribution of lesions. Hypopigmented lesions were present on the face in 12 (57.14%) patients. Histopathologically, hypopigmented lesions showed features of post-inflammatory hypopigmentation in 19% of patients, residual PLC in 52.4% and active PLC 28.6% of patients.

CONCLUSION: Hypopigmented lesions in PLC were noted mainly in younger ages, histopathologically they may show features of active or residual disease, beyond post-inflammatory hypopigmentation. Consequently active treatment for patients presenting predominantly with hypopigmented lesions could be required to control the disease.

Background: Skin involvement in granulomatosis with polyangiitis (GPA) is common and can appear as an initial presentation of the disease or more commonly through its course.

Case presentation: We report a case of a 24-year-old male patient, previously diagnosed as having GPA, admitted with fever, hemoptysis, generalized hemorrhagic blisters associated with arthralgia, fatigue, myalgia, nasal crusting, and vertigo. Three weeks prior to admission, he developed erythematous papules on both elbows, and purpuric papules on both lower limbs. Histopathological examination revealed: interstitial granulomatous dermatitis (elbows) and foci of dermal hemorrhage, foci of interstitial histiocytes and zones of altered necrobiotic collagen (lower limbs) consistent with cutaneous lesions of GPA. Two weeks later, his rash progressed to widespread purpura associated with hemorrhagic blisters. Another biopsy revealed leukocytoclastic vasculitis with fibrinoid necrosis of the vessel walls associated with perivascular infiltrate of neutrophils, nuclear dust and extravasated erythrocytes without an associated granulomatous inflammation or necrobiosis. The constellation of the results of the three biopsies together with clinical correlation pointed to a flare of GPA.

Conclusion: Skin involvement in GPA is quite common, and it can manifest in different forms in the same patient. Our patient developed three different skin pathologies within a short period of time.

Fractional CO laser rejuvenation of scars offers a high safety profile. Laser marks usually disappear clinically within 1 week. The authors observed occasional persistence of the laser marks on the scar surface. The purpose of this study is to report the incidence and to describe the clinical, dermoscopic, and histological features of a novel observed complication of fractional CO laser scar rejuvenation "Persistent Pixel Stamping Marks (PPSM)".One hundred seventy-one cases were consecutively recruited from patients assigned for fractional CO laser scar rejuvenation. Patients who developed the phenomenon 1 month post laser session were recorded and subjected to clinical photography, dermoscopy, and optical coherence tomography (OCT) as well as a 4-mm punch biopsy from pixelated scars. The evolution of PPSM was followed up for 6 months. PPSM developed in 16 patients (9.4%), 15 of which were post burn hypertrophic scars. PPSM was significantly related to darker skin type, darker scar color, and longer scar duration. Histopathological findings included characteristic holes in stratum corneum and superficial dermis, thick collagen bundles perpendicular to the skin surface with loss of elastic tissue, focal interface changes, and triangular focus of fibroblastic proliferation. The marks disappeared in 5 and lasted in 11 patients. Their longevity was significantly related to longer dwell times and lower densities. PPSM represent miniature scarring at the sites of the microscopic thermal zones or a sign of their delayed healing. They tend to follow fractional CO laser resurfacing of hyperpigmented, long-standing burn scars. Longer dwell times and lower densities make them last longer.

CLINICAL QUESTION: A 26-year-old woman presented with asymptomatic skin coloured to whitish keratotic papules on the vulva, inguinal folds and inner thighs of 6 years duration. She had no similar lesions elsewhere and no family history. A biopsy was taken from one of the papules.Review the high-quality, interactive digital Aperio slide at http://virtualacp.com/JCPCases/jclinpath-2018-205434/ and consider your diagnosis. WHAT IS YOUR DIAGNOSIS?: Darrier's diseaseHailey-Hailey diseaseGenital wartsPapular acantholytic dyskeratosis of genitocrural areaPemphigus vegetansThe correct answer is after the discussion.

DISCUSSION: Papular acantholytic dyskeratosis (PAD) of the genitocrural area is a peculiar acantholytic dermatosis with dyskeratosis localised to the vulva and inguinal folds with possible extension to the thighs and perineum.1 It mainly involves young or middle-aged females.1 Cases affecting males and involving genitalia, thighs and perianal region have been reported.2 It represents an allelic variant of Hailey-Hailey disease as heterozygous mutations in gene (intron 5 and exon 24) have been reported in some cases.3 Clinically, PAD of the genitocrural area is typically characterised by solitary or grouped keratotic flesh coloured or white papules.1 Other clinical presentations include: vesicles, bullae, patches and plaques.4 Although the lesions are mainly asymptomatic, patients may experience variable degrees of itching or burning sensation.Histopathologically, the lesions show hyperkeratosis, hypergranulosis, acanthosis and acantholytic dyskeratosis in the spinous layer (figure 1). Typically, direct immunoflourescence (DIF) is negative.5 jclinpath;jclinpath-2018-205434v1/F1F1F1Figure 1Photomicrograph representing histopathological findings: hyperkeratosis, hypergranulosis, acanthosis and acanthloytic dyskeratosis involving the spinous layer; 254×143 mm.The most important differential diagnoses of this sporadic condition include: Darier's and Hailey-Hailey, both of which are familial. Hailey-Hailey involves also other flexural areas and presents with eroded crusted lesions with foul odour. Pathologically, the acantholytic process in PAD of the genitocrural area is rather focal compared with the broad zone of acantholysis in Hailey-Hailey, and columns of parakeratosis overlying suprabasilar acantholysis are characteristic of Darier's disease. Although, some cases of PAD of the genitocrural area can present with vesicles and bullae, the presence of dyskeratotic cells and the negative DIF speaks against pemphigus.Treatment options for this condition include topical and systemic retinoids. Cryotherapy and laser have been also reported to be effective. Topical steroids might be effective in reducing pruritus.