Should we biopsy melanonychia striata in Asian children? A retrospective observational study.

BACKGROUND AND OBJECTIVES: Melanonychia striata is common in children of darker-skinned Asian races, while subungual melanoma is extremely rare and it is difficult to make a diagnosis clinically. However, performing nail unit biopsies in children is particularly challenging and can result in permanent nail dystrophy. The aim of this study was to review the clinical and histologic characteristics of melanonychia striata in pediatric patients of Asian descent to aid in the clinical decision regarding nail biopsy. METHODS: Sixty-two pediatric patients presenting with melanonychia striata involving single or multiple nails at two tertiary pediatric dermatology clinics in Singapore between 2005 and 2015 were reviewed. Clinical and histopathological data were analyzed, including age at onset, age at presentation, location, color, width, presence of Hutchinson's sign, pseudo-Hutchinson's sign, nail dystrophy, length of follow-up, and clinical evolution. Histopathological assessment was performed by three senior dermatopathologists independently for cases that underwent a nail biopsy. RESULTS: No cases of subungual melanoma were detected in our series. Solitary melanonychia of the thumbnail with a single uniform color was the most common presentation. Pseudo-Hutchinson's sign was commonly observed. Consensus in histological diagnosis emerged amongst all three dermatopathologists in only half of the cases biopsied. CONCLUSION: The occurrence of melanoma in Asian children presenting with melanonychia is extremely rare. We recommend clinical follow-up and anticipatory guidance for these patients and nail unit biopsy only in the presence of high-risk clinical features.

Recalcitrant psoriasiform dermatosis of the face: Is it related to pityriasis rubra pilaris?

BACKGROUND: There are patients with recalcitrant psoriasiform plaques that do not fit into conventional categories of facial dermatoses. Our study aims to describe the clinicopathological characteristics of several patients with a unique presentation of persistent psoriasiform facial rashes. METHODS: This retrospective cross-sectional study analyzed clinical and histological data of known cases of recalcitrant psoriasiform dermatosis of the face diagnosed at National Skin Centre, Singapore, over 10 years. RESULTS: There were 8 Chinese patients with mean age at onset of 29 years. Majority had pink to pink-orange well-defined plaques with dry scale (n = 6, 75%), distributed mostly on the cheeks (100%) and chin (n = 7, 88%). Hyperkeratosis, parakeratosis, preserved granular layer and psoriasiform hyperplasia were showed in all biopsies. Other common findings included subtle subcorneal acantholysis, "checkerboard" alternating ortho-/parakeratosis, vacuolated keratinocytes and follicular plugging. All patients showed little treatment response. One patient eventually developed features of type II pityriasis rubra pilaris (PRP). Our study was limited by its small sample size and lack of a pre-existing diagnostic code. CONCLUSIONS: This recalcitrant psoriasiform facial dermatosis seems to be a distinct entity, with consistent and reproducible clinical features and a PRP-like histology, bearing some resemblance to the recently described condition-facial discoid dermatosis.

Interstitial Granulomatous Variant of Scleromyxedema-A Diagnostic Pitfall.

Scleromyxedema is a rare disorder where patients may develop systemic manifestations such as monoclonal gammopathy, inflammatory polyarthritis, and esophageal and neurological dysfunction. Histologically, there may be atypical variants of scleromyxedema showing features resembling interstitial granuloma annulare. We report an unusual case of scleromyxedema with interstitial granulomatous pattern and highlight potential diagnostic pitfalls when encountered with such a variant.

Cutaneous Plasmacytosis: A Clinicopathologic Study of a Series of Cases and Their Treatment Outcomes.

INTRODUCTION: Cutaneous plasmacytosis (CP) is a rare skin disorder characterized by multiple reddish brown nodules with polyclonal plasma cell proliferation. It has most often been reported to affect the trunk but is also known to affect the face and extremities in adults and is predominantly seen in Asians. The etiology is poorly understood, and there is no consensus on treatment methods. METHODS: Five cases diagnosed to have CP were collated from our institution. Their clinicopathologic features and treatment outcomes were reviewed. RESULTS: Four of the 5 patients presented with lesions that affected multiple sites of the body including the trunk, axillae, face, and limbs. The remaining patient had lesions localized to his axillae. The lesions were generally asymptomatic. All patients had hypergammaglobulinaemia but only one had a faint monoclonal band detected on immunofixation. Common findings in the biopsy results for all patients were perivascular plasma cell infiltrates without light chain restriction on kappa/lambda staining, as well as mast cell infiltrates. Partial remission of cutaneous lesions was observed in 3 of the patients, with 2 of them responding well to psoralen and ultraviolet A radiation therapy. CONCLUSION: CP presents with distinctive clinical features and characteristic histological features including polyclonal perivascular plasma cell infiltrates. The axilla seems to be a frequent and characteristic site of involvement and may be a useful clinical clue to the condition. In the management of patients with CP, it is important to exclude secondary causes of plasmacytic infiltrates. While there are no clearly established treatment modalities for CP, psoralen and ultraviolet A radiation therapy may be a viable option in view of the clinical improvement observed in our patients who received it.

Reflectance confocal microscopy is a useful non-invasive tool in the in vivo diagnosis of pigmented basal cell carcinoma in Asians.

BACKGROUND: The clinical differentiation between pigmented basal cell carcinoma (BCC) and other benign pigmented skin lesions can be challenging even with an additional dermoscopic evaluation, especially if the lesion is small. In vivo reflectance confocal microscopy (RCM) is an emerging, non-invasive imaging tool that allows near-microscopic evaluation of skin lesions. The features of RCM for pigmented BCC and seborrhoeic keratosis have previously been described. However, the use of RCM to differentiate between these clinically and dermoscopically challenging pigmented skin lesions among Asians has not yet been demonstrated. OBJECTIVES: We aimed to evaluate the usefulness of non-invasive RCM to differentiate between clinically and dermoscopically challenging pigmented skin lesions among Asians in a series of 11 lesions. METHODS: Nine patients with 11 clinically and dermoscopically difficult to distinguish pigmented skin lesions were evaluated by RCM to differentiate between pigmented BCC and benign lesions. In all cases, a histological confirmation of the RCM diagnosis was obtained. RESULTS: The clinical or dermoscopical characteristics were non-specific in all 10 cases. RCM detected features of pigmented BCC in nine patients and seborrhoeic keratosis in one patient. These were all confirmed by histological examination. CONCLUSIONS: This case series shows the value of non-invasive in vivo RCM imaging in the differentiation of malignant and benign pigmented lesions. Early diagnosis of small, pigmented BCC allows earlier excision with better prognosis. Future biopsies of benign lesions in cosmetic areas could also be avoided.

Autoimmune manifestations of CTLA-4 haploinsufficiency in two patients of Southeast Asian ethnicity.

We report 2 patients who first developed cutaneous manifestations, followed by autoimmune phenomena, infections, and hypogammaglobulinemia. They were initially diagnosed with common variable immunodeficiency; however, the diagnosis was revised to cytotoxic T-lymphocyte antigen 4 haploinsufficiency after genetic and functional testing.

A case series of imatinib-induced generalized hypopigmentation and progression of existing acquired dermal melanocytosis.

Imatinib mesylate is a tyrosine kinase inhibitor used in the treatment of oncological conditions, including chronic myeloid leukemia and gastrointestinal stromal tumors. The most frequent dermatological side effect reported is pigmentary abnormalities. We report a case series of three Asian Chinese females with preexisting acquired dermal melanocytosis that progressed after initiation of imatinib treatment, and concurrently developed generalized hypopigmentation of the skin. All three patients had similar histological findings on skin biopsy. It is postulated that the KIT/SCF pathway has a central role in the pathogenetic mechanism. Therefore, it is important for physicians to be aware of this potential side effect of paradoxical pigmentation in patients treated with imatinib.

Radiological features of a rare case of pancreatic panniculitis presenting in bilateral lower extremities.

Pancreatic panniculitis is a rare cutaneous presentation in patients with pancreatic pathology. While it presents as cutaneous inflammation with painful and erythematous nodules which demonstrate ulceration, imaging features of this pathology are seldom described. The common sites of involvement are the extremities. It demonstrates characteristic histological features of lobular panniculitis with ghost cells. MR imaging with its excellent soft tissue contrast can be helpful in confirming the diagnosis, demonstrating imaging features of fat necrosis with surrounding inflammation as demonstrated in our patient.

Hypopigmentation Induced by Frequent Low-Fluence, Large-Spot-Size QS Nd:YAG Laser Treatments.

The Q-switched 1064-nm neodymium-doped yttrium aluminum garnet (QS 1064-nm Nd:YAG) laser is increasingly used for nonablative skin rejuvenation or "laser toning" for melasma. Multiple and frequent low-fluence, large-spot-size treatments are used to achieve laser toning, and these treatments are associated with the development of macular hypopigmentation as a complication. We present a case series of three patients who developed guttate hypomelanotic macules on the face after receiving laser toning treatment with QS 1064-nm Nd:YAG.

Pruritus, pain, and small nerve fiber function in keloids: a controlled study.

BACKGROUND: Keloid scars can itch and hurt, but little is known about the characteristics of these symptoms in keloids. Because itch and pain are carried by small nerve fibers, abnormal function of these fibers could be an explanation for such phenomena. OBJECTIVE: We sought to assess the characteristics of itch and pain in keloid scars, and to assess the function of small nerve fibers in keloids. METHODS: We studied the location and intensity of itch and pain in keloids that had been present for at least 1 year. We further studied the function of small nerve fibers by assessing allodynia and alloknesis (which are pain and itch, respectively) from innocuous stimuli that do not normally provoke pain and itch, and we used quantitative thermosensory testing (in keloid lesions, perikeloidal skin, and contralateral normal skin as a control). Results In all, 28 patients (13 men and 15 women) with a mean age of 34 years were enrolled and completed the study. Of the patients, 86% experienced itch and 46% experienced keloid-related pain. Of those who experienced itch, 92% felt the itch at the edge of their keloids. Of the patients with pain, 77% felt pain at the center of the keloid. Mechanical allodynia was noted in 43% of the patients, and only 14% experienced alloknesis. Abnormal thermosensory thresholds to warmth, cold, and heat pain were noted in the keloids. Visual analogue scale of itch correlated significantly to warmth ( r = 0.65), heat pain ( r = 0.4), and cold pain ( r = -0.41). CONCLUSION: Itch and pain are common presentations in keloids and are associated with abnormalities in small nerve fiber function, suggesting a small nerve fiber neuropathy.

Successful Treatment of Tattoo-Induced Pseudolymphoma with Sequential Ablative Fractional Resurfacing Followed by Q-Switched Nd: YAG 532 nm Laser.

Decorative tattooing has been linked with a range of complications, with pseudolymphoma being unusual and challenging to manage. We report a case of tattoo-induced pseudolymphoma, who failed treatment with potent topical and intralesional steroids. She responded well to sequential treatment with ablative fractional resurfacing (AFR) followed by Q-Switched (QS) Nd:YAG 532 nm laser. Interestingly, we managed to document the clearance of her tattoo pigments after laser treatments on histology and would like to highlight the use of special stains such as the Grocott's Methenamine Silver (GMS) stain as a useful method to assess the presence of tattoo pigment in cases where dense inflammatory infiltrates are present.

Case of primary localized cutaneous amyloidosis with protean clinical manifestations: lichen, poikiloderma-like, dyschromic and bullous variants.

Primary localized cutaneous amyloidosis (PLCA) commonly presents as macular and lichen variants. We present a case of a 27-year-old Chinese woman with cutaneous features of the rarely reported poikiloderma-like, dyschromic and bullous forms of PLCA, and the commoner lichen variant. There were no syndromic associations or systemic involvement, and the various morphological subtypes occurred in isolation from one another. We review the clinical spectrum of PLCA, highlight its protean clinical manifestations in this patient, and discuss its postulated pathogenesis in relation to its histopathological features.