Topical Methimazole as a New Treatment for Postinflammatory Hyperpigmentation: Report of the First Case

Management of the Sequelae of Skin Grafting: Pruritis, Folliculitis, Pigmentation Changes, and More

Scars commonly give rise to unpredictable, potentially irritating, cutaneous complications including pruritis, folliculitis, and pigment changes. These problems can be self-limiting and are prevalent in many burn cases, although their expression varies among individuals. A better understanding of the presentation, risk factors, and pathophysiology of these long-term sequelae allows for more comprehensive care of burn survivors.

Update on Melasma Treatments

Melasma is a prevalent hyperpigmentation condition known for its challenging treatment due to its resemblance to photoaged skin disorders. Numerous studies have shed light on the intricate nature of melasma, which often bears similarity to photoaging disorders. Various therapeutic approaches, encompassing topical and systemic treatments, chemical peeling, and laser therapy, have exhibited efficacy in managing melasma in previous research. However, melasma often reoccurs despite successful treatment, primarily due to its inherent photoaged properties. Given that melasma shares features with photoaging disorders, including disruptions in the basement membrane, solar elastosis, angiogenesis, and mast cell infiltration in the dermal layer, a comprehensive treatment strategy is imperative. Such an approach might involve addressing epidermal hyperpigmentation while concurrently restoring dermal components. In this article, we provide a comprehensive review of conventional treatment methods frequently employed in clinical practice, as well as innovative treatments currently under development for melasma management. Additionally, we offer an extensive overview of the pathogenesis of melasma.

Comparative effectiveness and safety of topical methimazole 5% monotherapy versus combination of Q-Switched Nd: YAG Laser and topical methimazole 5% in patients with refractory melasma

INTRODUCTION

Melasma is an acquired pigmentary disorder which currently has no definitive treatment. Although topical drugs containing hydroquinone are the basis of treatments, they are usually associated with recurrence. We aimed to evaluate the effectiveness and safety of monotherapy with topical methimazole 5% versus combination of Q-Switched Nd: YAG Laser and topical methimazole 5% in patients with refractory melasma.

METHODS

A total of 27 women with refractory melasma were included. We applied topical methimazole 5% (once a day) with three passes of QSNd: YAG laser (Wavelength: 1064 nm, pulse energy: 750 mJ, fluence: 1.50  J/cm² , spot size: 4 × 4 mm, hand piece: fractional, JEISYS company) for six sessions on the right half of the face, and topical methimazole 5% (once a day) on the left half of the face, for each patient. The treatment course was 12 weeks. Evaluation of effectiveness was done with the Physician Global Assessment (PGA), Patient Global Assessment (PtGA), Physician satisfaction (PS), Patients satisfaction (PtS), and mMASI score.

RESULTS

PGA, PtGA, and PtS were not significantly different between the two groups at any time (p > 0.05). PS in the laser plus methimazole group was significantly better than methimazole group at 4th, 8th, and 12th weeks (p < 0.05). The rate of PGA improvement in the combination group was significantly better than the monotherapy over time (p < 0.001). The changes of mMASI score between the two groups did not significantly differ at any time (p > 0.05). There was no significant difference in the adverse events between the two groups.

CONCLUSION

Combination therapy with topical methimazole 5% and QSNY laser can be considered as an effective way to treat refractory melasma.

Treatment of hyperpigmentation after burn: A literature review

OBJECTIFY

Skin pigmentation disorders are one of the most frequent sequelae after burn injury. While these conditions often improve over time, some are permanent and cause severe psychological disorders (especially on the face). Given the frequency of these disorders and their benign nature, the scientific community has great difficulty postponing these patient follow-ups. Publications on their management are rare, and there is no consensus on the gold standard treatment for skin dyschromia. Herein, we performed a literature review including the various treatments currently proposed to manage these hyperpigmentations.

METHODS

All reported articles up to February 2021 were reviewed on Pubmed. Studies on the treatment of hyperpigmented scars were included if they were secondary to burn injuries. Excluded articles evaluated transient treatments, such as makeup, and articles on inflammatory hyperpigmentation without etiological details or not secondary to burns.

RESULTS

201 articles were identified, and 13 studies were included. Topical creams used in inflammatory hyperpigmented lesions such as hydroquinone and first-line retinoids are controversial due to their inconstant efficacy. Various types of laser and pulsed light treatments have shown their effectiveness but can also aggravate pigmentation.

CONCLUSION

Dyschromia after burn remains a therapeutic challenge. Hyperpigmentations after burn should be treated on a case-by-case basis, using data from the literature, clinical experience and measuring the risk/benefit ratio.

Efficacy of Cysteamine and Methimazole in Treating Melasma A Comparative Narrative Review

Melasma is a chronic and acquired pigmentary condition that primarily affects women and undermines patient satisfaction and confidence. Melasma mostly affects females, accounting for 90% of all cases. It affects people of all races, particularly those with skin types IV and V who live in areas with lots of UV radiation. According to the studies, Melasma lesions are seen throughout the face in centrofacial, malar, and mandibular patterns. Melasma lesions on the forehead, cheeks, nose, upper lip, and/or chin are the most prevalent centrofacial pattern. Melasma lesions can also be detected along the periorbital area, especially in Asian people. Melasma is notably resistant to treatment, with many patients experiencing only temporary relief and relapses. Combining therapies that target numerous pathologic components, including photodamage, inflammation, aberrant vascularity, and abnormal pigmentation, generally results in the most dramatic therapeutic improvements. Treatments for dark circles include topical depigmenting medicines like hydroquinone, kojic acid, azelaic acid, and topical retinoic acid, and physical treatments such as chemical peels, surgical adjustments, and laser therapy. The objective of therapy should be to figure out what's causing the hyperpigmentation and what's contributing to it. This article provides an overview of melasma therapies and the efficacy of methimazole and cysteamine for melasma therapy.

The pathogenesis of melasma and implications for treatment

BACKGROUND

Melasma is a complex and poorly understood disorder, with high rates of treatment failure and recurrences.

OBJECTIVES

We aimed to review the current knowledge of the pathogenesis of melasma and apply this knowledge to clinical implications on relevant therapeutic interventions.

METHODS

A systematic PubMed search was performed using the search term "((melasma[Text Word]) OR facial melanosis[Text Word]) AND (pathogenesis OR causality[MeSH Terms])" for articles published between 1990 and 2020. Included articles were then evaluated by two authors and assessed for relevant pathomechanistic pathways, after which they were divided into groups with minimal overlap. We then reviewed current treatment modalities for melasma and divided them according to the involved pathomechanistic pathway.

RESULTS

A total of 309 search results were retrieved among which 76 relevant articles were identified and reviewed. Five main pathomechanisms observed in melasma were identified: (1) melanocyte inappropriate activation; (2) aggregation of melanin and melanosomes in dermis and epidermis; (3a) increased mast cell count and (3b) solar elastosis; (4) altered basement membrane; and (5) increased vascularization. Treatment modalities were then divided based on these five pathways and detailed in 6 relevant tables.

CONCLUSION

The pathophysiology of melasma is multifactorial, resulting in treatment resistance and high recurrence rates. This wide variety of pathomechanisms should ideally be addressed separately in the treatment regimen in order to maximize results.

New oral and topical approaches for the treatment of melasma

Melasma is a common, therapeutically challenging, and universally relapsing disorder of hyperpigmentation that is most often observed in women and individuals with Fitzpatrick Skin Types III through VI. The pathogenesis of melasma is complex and protean. Contributing factors that are often implicated in the etiopathogenesis of this condition include a genetic predisposition, intense ultraviolet radiation exposure, and hormonal influences. Therapeutic interventions for melasma include a multimodality approach incorporating photoprotection agents, topical and oral skin lighteners, and resurfacing procedures. Given our expanding knowledge of the pathogenesis of melasma, new and effective treatments are expanding our therapeutic armamentarium. This article reviews new and emerging oral and topical treatments for melasma.

Potent anti-melanogenic activity and favorable toxicity profile of selected 4-phenyl hydroxycoumarins in the zebrafish model and the computational molecular modeling studies

7-Hydroxy-4-phenylcoumarin (7C) and 5,7-dihydroxy-4-phenylcoumarin (5,7C) have been evaluated as potential anti-melanogenic agents in the zebrafish (Danio rerio) model in comparison to commercially utilized depigmenting agents hydroquinone and kojic acid. 7C and 5,7C decreased the body pigmentation at 5 µg/mL, while did not affect the embryos development and survival at doses ≤50 µg/mL and ≤25 µg/mL. Unlike hydroquinone and kojic acid, 4-phenyl hydroxycoumarins were no melanocytotoxic, showed no cardiotoxic side effects, neither caused neutropenia in zebrafish embryos, suggesting these compounds may present novel skin-whitening agents with improved pharmacological properties. Inhibition of tyrosinase was identified as the possible mode of anti-melanogenic action. Molecular docking studies using the homology model of human tyrosinase as well as adenylate cyclase revealed excellent correlation with experimentally obtained results.

Inorganic layered double hydroxides as a 4-hexyl resorcinol delivery system for topical applications

In this study, the hydrophobic even skin tone active, 4-hexylresorcinol is intercalated into a Zn–Al layered double hydroxide by co-precipitation method and used as controlled release ingredient in a skin care formulation.

Hypothyroidism improves random-pattern skin flap survival in rats

BACKGROUND

The protective effect of hypothyroidism against ischemic or toxic conditions has been shown in various tissues. We investigated the effect of propylthiouracil (PTU)/methimazole (MMI)-induced hypothyroidism and acute local effect of MMI on the outcome of lethal ischemia in random-pattern skin flaps.

MATERIALS AND METHODS

Dorsal flaps with caudal pedicles were elevated at midline and flap survival was measured at the seventh day after surgery. The first group, as control, received 1 mL of 0.9% saline solution in the flap before flap elevation. In groups 2 and 3, hypothyroidism was induced by administration of either PTU 0.05% or MMI 0.04% in drinking water. The next four groups received local injections of MMI (10, 20, 50, or 100 μg/flap) before flap elevation. Local PTU injection was ignored due to insolubility of the agent.

RESULTS

Hypothyroidism was induced in chronic PTU- and MMI-treated groups, and animals in these groups showed significant increase in their flap survival, compared to control euthyroid rats (79.47% ± 10.49% and 75.48% ± 12.93% versus 52.26% ± 5.75%, respectively, P < 0.01). Acute local treatment of skin flaps with MMI failed to significantly affect the flap survival.

CONCLUSION

This study demonstrates for the first time that hypothyroidism improves survival of random-pattern skin flaps in rats.

Postinflammatory hyperpigmentation: etiologic and therapeutic considerations

Postinflammatory hyperpigmentation (PIH) is a reactive hypermelanosis and sequela of a variety of inflammatory skin conditions. PIH can have a negative impact on a patient's quality of life, particularly for darker-skinned patients. Studies show that dyschromias, including PIH, are one of the most common presenting complaints of darker-skinned racial ethnic groups when visiting a dermatologist. This is likely due to an increased production or deposition of melanin into the epidermis or dermis by labile melanocytes. A variety of endogenous or exogenous inflammatory conditions can culminate in PIH and typically most epidermal lesions will appear tan, brown, or dark brown while dermal hypermelanosis has a blue-gray discoloration. Depigmenting agents target different steps in the production of melanin, most commonly inhibiting tyrosinase. These agents include hydroquinone, azelaic acid, kojic acid, arbutin, and certain licorice (glycyrrhiza) extracts. Other agents include retinoids, mequinol, ascorbic acid (vitamin C), niacinamide, N-acetyl glucosamine, and soy, and these products depigment by different mechanisms. Certain procedures can also be effective in the treatment of PIH including chemical peeling and laser therapy. It is important to note that these same therapeutic modalities may also play a role in causing PIH. Lastly, those lesions that are not amenable to medical or surgical therapy may experience some improvement with cosmetic camouflage.

Management of severe thyrotoxicosis when the gastrointestinal tract is compromised

BACKGROUND

The management of patients with severe thyrotoxicosis in the absence of a functional gastrointestinal tract represents an uncommon but significant clinical challenge associated with a high mortality rate. This article offers a literature review and discussion of the available management options in this setting.

SUMMARY

Treatment of severe thyrotoxicosis in patients unable to ingest medications by the oral route should focus on normalization of thyroid hormone levels utilizing conventional medical therapy for thyrotoxicosis, administered via non-oral routes. This includes thionamides, beta-blockers, iodine containing solutions, and glucocorticoids. When conventional medical therapy fails, plasmapheresis should be considered as a temporary therapeutic bridge until conventional therapies can be instituted effectively or emergent surgery performed.

CONCLUSION

Although a rare scenario, the management of patients with severe thyrotoxicosis in the absence of a functional gastrointestinal tract represents a challenging clinical situation. Endocrinologists and critical care physicians should be apprised of the available treatment modalities which must be instituted swiftly in order to avoid a catastrophic outcome.

Advanced diagnostic approaches and current management of thyroid pathologies in Guinea pigs

The authors have encountered multiple clinical cases of clinical hyperthyroidism in the guinea pig, which responded positively to clinical treatment. Hyperactive thyroids in the guinea pig appear to exist causing typical clinical signs. An early accurate diagnosis of this pathologic state is important in the clinical setting. One of the authors has encountered a few clinical cases of hypothyroidism in guinea pigs. Hypothyroidism appears to be a rare condition and has been described anecdotally in the German literature. Because of the rarity of hypothyroidism, the text focuses mainly on the guinea pig as a hyperthyroid case. A short description of the clinical presentation of the hypothyroid animal is included at the end of the text.