Many febrile diseases caused by ribonucleic acid virus infection demonstrate cutaneous manifestations with preceding prodromes. This review provides a flowchart highlighting the diagnostic clues of viral exanthem. Besides febrile prodromes, patients with chikungunya virus have severe arthralgias and macular hyperpigmentation on the noses. Coronavirus disease 2019 demonstrates unique acrocyanosis and pseudofrostbite besides erythematous rash and urticaria, suggesting abnormal coagulation. Dengue fever should be suspected when patients in the tropical region present with biphasic fever, headache, retroorbital pain, and centrifugal morbilliform rash. Dengue hemorrhagic fever, a potentially fatal complication, results from systemic vascular leakage. High-temperature fever and sudden-onset severe headache raise the possibility of Ebola virus infection. Patients with hand-foot-and-mouth disease may experience morbilliform or vesicular eruption, especially over the hands, feet, and oral mucosa. In acute human immunodeficiency virus infection, maculopapular eruptions often appear on the face and neck after prodromes. Primary human T-lymphotropic-III virus infection can induce widespread maculopapular or roseola-like exanthem, sparing the hands and feet. Cutaneous manifestations of rotavirus include generalized maculopapular rash, Sweet's syndrome, Henoch–Schonlein purpura, Gianotti–Crosti syndrome, and acute hemorrhagic edema. Rubella is usually suspected when low-grade fever and lymphadenopathy are accompanied by a discrete pinpoint-sized maculopapular rash, which spreads and diminishes faster than measles. Cough, coryza, and conjunctivitis followed by morbilliform eruptions and Koplik's spots are diagnostic of measles. Exanthem of Zika virus comprised of small pruritic papules that extend downwards. Laboratory testing is helpful in making a definitive diagnosis. Viral isolation, measurement of immunoglobulin M (IgM) or IgG, and/or reverse transcription polymerase chain reaction are useful diagnostic tools with favorable sensitivity and specificity.

Hepatitis B virus (HBV) infection is a critical public health issue worldwide. The prompt recognition of skin diseases associated with HBV enables the earlier diagnosis of undetected HBV infection. This review article aims to provide a guide for physicians to increase awareness of possible HBV infection when encountering skin diseases. The frequencies of HBV infection were highest in telangiectasia macularis multiplex acquisita, followed by mixed cryoglobulinemia (MC), polyarteritis nodosa (PAN), and Gianotti-Crosti syndrome (GCS). Serology tests for HBV are recommended for patients with the above diseases. Lichen planus is not associated with HBV according to the most recent evidence. Chronic urticaria and porphyria cutanea tarda are associated with HBV infection although the detection rate of HBV was only 2% in these two diseases. The mechanism behind the associations between HBV and these skin disorders remains unknown and virus-associated immune-mediated processes or direct injury caused by viral replication are frequently proposed. The clinical manifestation was not discrepant between the HBV-associated skin disorder and the non-HBV-associated counterpart. The duration of HBV infection did not show any statistically significant correlations with the development of skin disorders. Antiviral medication yielded improvement in HBV-associated PAN, MC and GCS.

Background: In recent years, many studies have reported that amniotic membrane (AM) is an effective adjuvant for promoting the healing of chronic cutaneous ulcers (CCUs). Objectives: The objective of the present study was to evaluate the efficacy and safety of AM for the topical treatment of CCUs. Methods: A literature search was performed using PubMed, Cochrane Library, and Embase for all related studies from inception to May 31, 2019, without restriction on language. A quantitative synthesis of randomized controlled trials (RCTs) was conducted to compare the effectiveness and safety between the AM therapy and standard of care/conventional treatment by employing a random-effect model. Results: Thirteen RCTs with 947 patients were included in the study. Compared to standard of care (SOC), the relative risk (RR) for the healing rate was 1.99 (95% confidence interval [CI]: 1.75–2.26, P < 0.001). A greater percentage area reduction could be found in AM group (mean difference = 70.00%, 95% CI: 15.82–124.17, P = 0.01). There was no statistically significant difference in pain relief (P = 0.36). The RR for adverse events was estimated 0.54 (95% CI: 0.31–0.93) when compared AM group with SOC group (P = 0.03). Conclusion: This systematic review and meta-analysis indicate that it is effective and safe to use AM as an adjuvant treatment for treating CCUs.

Background: Altered microbiota of the gastrointestinal tract have been implicated in both atopic dermatitis (AD) and inflammatory bowel disease (IBD). However, the relationship between AD and IBD has been unclear. Objectives: The objective of this study was to systemically assess the evidence on the association of AD with IBD. Methods: We conducted a systematic review and meta-analysis of observational studies on the association of AD with IBD. We searched MEDLINE, Embase, CENTRAL, Web of Science, and Airiti Library from inception to May 24, 2019, for relevant studies. The outcomes were the odds and risk of Crohn's disease (CD) and ulcerative colitis (UC) in patients with AD. Results: We included five case–control studies and one cohort study. We identified significant associations of AD with prevalent CD (odds ratio [OR]: 1.55, 95% confidence interval [CI]: 1.11–2.15) and UC (OR: 2.49, 95% CI: 1.04–5.98). One Danish cohort study found no increased risk for incident CD (hazard ratio [HR]: 0.69, 95% CI: 0.34–1.30) and UC (HR: 0.94, 95% CI: 0.61–1.43) in patients with AD. Conclusion: The current limited evidence supports an association of AD with prevalent IBD. Digestive symptoms in patients with AD, for example, chronic diarrhea and abdominal pain, shall not be overlooked, and gastroenterology counseling may be needed.

Background: The associations between psoriasis, metabolic syndrome, and cardiovascular events are increasingly recognized. Studies have shown decreased cardiovascular events with the treatment of methotrexate and anti-tumor necrosis factor-α. However, effects of interleukin (IL)-12/23 blockade remain debatable. Objectives: Our study sought to investigate the effect of IL-12/23 blockade on the metabolic parameters in patients with psoriasis. Methods: We performed a retrospective cohort study to assess 93 consecutive patients with moderate-to-severe plaque-type psoriasis who received IL-12/23 blockade (ustekinumab) for 24 weeks between January 2012 and May 2016. Results: Metabolic parameters and disease activity (psoriasis area severity index score) at baseline and 24 weeks of treatment were collected. At week 24 (wk24), the disease activity improved significantly (mean: baseline, wk0: 21.35 ± 11.55 to wk24: 6.87 ± 6.81, P < 0.0001), with a significant reduction of erythrocyte sedimentation rate. Conversely, body mass index was significantly elevated in PASI-75 responders at wk24 of treatment and was independent of disease severity. Fasting sugar and triglyceride level were elevated at wk24. Cholesterol (Chol), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) remained unchanged. These metabolic parameters were not correlated with the improvement in disease severity after ustekinumab treatment. Nonetheless, the atherogenic index, LDL/HDL ratio, and Chol/HDL ratio remained unchanged. Male gender is a predictor of elevated plasma triglyceride level. Conclusion: Our results suggest that despite tremendous improvement in disease activity after ustekinumab treatment, obesity, fasting sugar, and hypertriglyceridemia are still present in these patients. Regular screening of lipid profile and obesity control is advised during the treatment of ustekinumab, especially in male psoriasis patients with predisposing cardiovascular risks.

X-linked hypohidrotic ectodermal dysplasia (XLHED) is caused by EDA pathogenic variants. Female carriers show several clinical manifestations in variable percentages. We studied 11 Mexican heterozygous females with an EDA variant. The most frequent symptoms were similar to previous reports; however, two females (18%) reported dry eye syndrome, data rarely explored in carriers. The penetrance was 91% with clinical variability that might be related to the location of the mutation and/or to a skewed X-inactivation pattern. Our results highlight the importance of offering molecular testing to potential female carriers and support XLHED as an X-linked entity with incomplete penetrance in females.

The non-Langerhans cell histiocytoses (non-LCH) are rare and benign histiocytic disorders. We present a 61-year-old female with progressive skin-colored nodules on the face and extremities. The skin biopsy showed dermal infiltration of foamy histiocytes. Further imaging study showed erosive arthritis and lymphadenopathy. The microscopical feature of anterior mediastinal lymph node was similar to that in the skin. Thus, the diagnosis is non-LCH with joints and lymph nodes involvement. This patient presented both the clinical manifestations of multicentric reticulohistiocytosis (MRH) and histologic findings of xanthoma disseminatum (XD), indicating the plausible association and the shared disease spectrum of MRH and XD.