There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

The 11th edition of Harrison's Principles of Internal Medicine welcomes Anthony Fauci to its editorial staff, in addition to more than 85 new contributors. While the organization of the book is similar to previous editions, major emphasis has been placed on disorders that affect multiple organ systems. Important advances in genetics, immunology, and oncology are emphasized. Many chapters of the book have been rewritten and describe major advances in internal medicine. Subjects that received only a paragraph or two of attention in previous editions are now covered in entire chapters. Among the chapters that have been extensively revised are the chapters on infections in the compromised host, on skin rashes in infections, on many of the viral infections, including cytomegalovirus and Epstein-Barr virus, on sexually transmitted diseases, on diabetes mellitus, on disorders of bone and mineral metabolism, and on lymphadenopathy and splenomegaly. The major revisions in these chapters and many

Harrison's Principles of Internal Medicine

Secret History: Return of the Black Death Channel 4, 7-8pm In 1348 the Black Death swept through London, killing people within days of the appearance of their first symptoms. Exactly how many died, and why, has long been a mystery. This Secret History documentary follows experts as they pick through the evidence and reveal why the plague killed on such a scale. And they ask, what might be coming next?

Medscape

Chronic urticaria. I

Wound care is a major healthcare expenditure. Treatment of burns, surgical and trauma wounds, diabetic lower limb ulcers and skin wounds is a major medical challenge with current therapies largely focused on supportive care measures. Successful wound repair requires a series of tightly coordinated steps including coagulation, inflammation, angiogenesis, new tissue formation and extracellular matrix remodelling. Zinc is an essential trace element (micronutrient) which plays important roles in human physiology. Zinc is a cofactor for many metalloenzymes required for cell membrane repair, cell proliferation, growth and immune system function. The pathological effects of zinc deficiency include the occurrence of skin lesions, growth retardation, impaired immune function and compromised would healing. Here, we discuss investigations on the cellular and molecular mechanisms of zinc in modulating the wound healing process. Knowledge gained from this body of research will help to translate these findings into future clinical management of wound healing.

https://www.mdpi.com/2072-6643/10/1/16/pdf/1

Zinc in Wound Healing Modulation.

Zinc, both in elemental or in its salt forms, has been used as a therapeutic modality for centuries. Topical preparations like zinc oxide, calamine, or zinc pyrithione have been in use as photoprotecting, soothing agents or as active ingredient of antidandruff shampoos. Its use has expanded manifold over the years for a number of dermatological conditions including infections (leishmaniasis, warts), inflammatory dermatoses (acne vulgaris, rosacea), pigmentary disorders (melasma), and neoplasias (basal cell carcinoma). Although the role of oral zinc is well-established in human zinc deficiency syndromes including acrodermatitis enteropathica, it is only in recent years that importance of zinc as a micronutrient essential for infant growth and development has been recognized. The paper reviews various dermatological uses of zinc.

/pdf/zinc-therapy-in-dermatology-a-review-12gq8lknl0.pdf

Zinc therapy in dermatology: a review.

Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors and comprise three different isoforms namely PPARα, PPARγ, and PPARβ/δ with PPARβ/δ being the predominant subtype in human keratinocytes. After binding with specific ligands, PPARs regulate gene expression, cell growth and differentiation, apoptosis, inflammatory responses, and tumorogenesis. PPARs also modulate a wide variety of skin functions including keratinocyte proliferation, epidermal barrier formation, wound healing, melanocyte proliferation, and sebum production. Recent studies have shown the importance of PPARs in the pathogenesis of many dermatological disorders. Clinical trials have suggested possible role of PPAR agonists in the management of various dermatoses ranging from acne vulgaris, psoriasis, hirsutism, and lipodystrophy to cutaneous malignancies including melanoma. This article is intended to be a primer for dermatologists in their understanding of clinical relevance of PPARs and PPAR agonists in dermatology therapeutics.

Peroxisome proliferator-activated receptors (PPARs) and PPAR agonists: the ‘future’ in dermatology therapeutics?

SummaryBackground
Tranexamic acid (TXA) has been used orally, intravenously, topically and intradermally (microinjection, microneedling) for treating melasma. However, the comparative efficacy of these different routes of administration remains underevaluated.

Aim
To ascertain the comparative efficacy of different routes of administration of TXA.

Methods
In total, 100 consecutive patients with melasma (8 men, 92 women, age range 18–55 years) were randomly assigned to one of two groups comprising 50 patients each. Group A (3 men, 47 women) received oral TXA 250 mg twice daily, while group B (5 men, 45 women) received intradermal microinjections of TXA 4 mg/mL every 4 weeks. The treatment continued for 12 weeks in both groups. Percentage reduction in baseline Melasma Area and Severity Index (MASI) was assessed at 4-week intervals, and response was scored as very good (> 75% reduction), good (50% to < 75% reduction), moderate (25% to < 50% reduction), mild (< 25% reduction) or no response.

Results
The study was completed by 39 patients in group A and 41 patients in group B. Very good response was seen in 25 and 32 patients in groups A and B, respectively, while good response was seen in 14 and 9 patients, respectively. Both treatment methods were equally effective, with an average reduction of MASI at 12 weeks of 77.96 ± 9.39 in group A and 79.00 ± 9.64 in group B. The main adverse effects were mild epigastric discomfort, hypomenorrhea, headache and injection site pain, which did not warrant discontinuation of treatment. Two patients in group A had relapses at 24 weeks.

Conclusion
TXA appears to be an effective and safe treatment for melasma, irrespective of its route of administration.

Therapeutic efficacy and safety of oral tranexamic acid and that of tranexamic acid local infiltration with microinjections in patients with melasma: a comparative study

Background

Subcutaneous phaeohyphomycosis usually results from traumatic inoculation with the fungus and generally occurs in immunosuppressed men. Cladosporium, Exophiala, and Alternaria spp. are commonly implicated pathogens.



Objectives

We present a case of subcutaneous phaeohyphomycosis caused by Rhytidhysteron sp. that was refractory to conventional antifungal therapy.



Case report

A 72-year-old man with hypertension and diabetes presented with a multiloculated, large cystic swelling over the right dorsal foot. Laboratory findings and x-rays of the chest and left foot were normal.



Results

Adequate control of the patient's diabetes was achieved, and the swelling was excised under itraconazole/terbinafine coverage. Histology showed multiple areas of neutrophilic abscess, epithelioid cells, foreign body giant cells, and multiple septate hyphae and yeast-like cells. Dematiaceous fungus was cultured but failed to produce spores. Sequencing of the isolate showed a match of > 99% with Rhytidhysteron rufulum. The patient demonstrated no response after one year of therapy with itraconazole/terbinafine. Weekly infiltration of the lesion with liposomal amphotericin B resulted in its complete resolution within 15 weeks.



Conclusions

Lesions of phaeohyphomycosis appear morphologically similar regardless of the organism implicated. Hence, their diagnosis rests entirely on the clinicopathological and microbiological presentation. Molecular studies may be required to identify a fungus if attempts to grow it in artificial culture media fail. Rhytidhysteron spp. are not known as pathogens in humans, and no treatment protocol exists. Intralesional amphotericin was highly effective in our patient and caused no systemic adverse effects. Voriconazole and posaconazole are effective against disseminated/visceral phaeohyphomycotic infections, but their efficacy against Rhytidhysteron spp. remains unstudied.

A rare case of subcutaneous phaeohyphomycosis caused by a Rhytidhysteron species: a clinico-therapeutic experience.

Background: Most therapeutic modalities for common warts remain unsatisfactory. Objectives: To evaluate efficacy and safety of intralesional MMR (measles, mumps, rubella virus) vaccine in the treatment of common warts in adults. Patients and Methods: There were 110 (M:F = 61:49) patients aged 19–62 years having 1–211 warts over dorsal hands, feet, palms, soles, and periungual skin for 1–252 months. MMR vaccine 0.25 mL was injected intralesionally in the largest wart and repeated at 2-week interval until complete clearance or maximum of five doses. The outcome was evaluated as complete clearance, excellent, good, or unsatisfactory response on visual analog scale at every visit and at 4 and 8 weeks, thereafter by comparing baseline clinical photograph. Likert scale was used for patient satisfaction level assessment similarly. Results: Only 51 patients completed the study and 42 (82.4%) of them showed complete clearance of warts and 9 (17.6%) patients showed good or unsatisfactory response. In 4 (7.8%) patients, the warts subsided completely after one dose itself. The four patients showing excellent response after five doses initially also continued to improve during follow-up period of 8 weeks. Except for injection site pain, no adverse effects were noted. There was no recurrence of warts among cured who were also very much satisfied from treatment. Conclusion: Despite variable results, intralesional MMR vaccine immunotherapy appears another possible safe and effective treatment option for common warts in a set of adult patients with advantages of regression of distant warts, no significant adverse effects and low recurrence. However, well-designed, controlled studies for minimum effective dose and treatment schedule are highly desirable to make any recommendation.

Karaninder S Mehta

Papers

Zinc therapy in dermatology: a review.

Peroxisome proliferator-activated receptors (PPARs) and PPAR agonists: the ‘future’ in dermatology therapeutics?

Therapeutic efficacy and safety of oral tranexamic acid and that of tranexamic acid local infiltration with microinjections in patients with melasma: a comparative study

A rare case of subcutaneous phaeohyphomycosis caused by a Rhytidhysteron species: a clinico-therapeutic experience.

The efficacy and safety of intralesional immunotherapy with measles, mumps, rubella virus vaccine for the treatment of common warts in adults