Topical tacrolimus significantly promotes repigmentation in idiopathic guttate hypomelanosis: a double-blind, randomized, placebo-controlled study

Efficacy and Safety of 5-Fluorouracil Tattooing to Repigment Idiopathic Guttate Hypomelanosis: A Split-Body Randomized Trial

BACKGROUD

Idiopathic guttate hypomelanosis (IGH) is a common skin disorder with no standard treatment.

OBJECTIVE

Assess the efficacy and safety of 5-fluorouracil (5FU) compared with saline, delivered using a tattoo machine, to repigment IGH lesions.

METHODS

This split-body randomized single-blinded trial recruited adults with symmetrical IGH lesions. A tattoo machine was used to deliver 5FU in IGH lesions of 1 limb and saline in the contralateral limb. Outcomes were the number of achromic lesions 30 days after treatment compared with baseline, patient satisfaction, and local or systemic adverse events.

RESULTS

Twenty-nine patients (28 women) were included. The median number of achromic lesions decreased significantly in 5FU-treated limbs (baseline: 32, interquartile range (IQR) 23-37 × post-treatment: 12, IQR 6-18, p = .000003) and saline-treated limbs (baseline: 31, IQR 24-43 × post-treatment: 21, IQR 16-31, p = .000006), but reduction was significantly more pronounced in 5FU-treated limbs ( p = .00003). All participants were satisfied or very satisfied with results on 5FU-treated limbs. There were no adverse events.

CONCLUSION

5-fluorouracil delivery using a tattoo machine was more effective than saline to repigment IGH lesions, with high patient satisfaction and no adverse events.Clinicaltrials.gov : NCT02904564.

Idiopathic guttate hypomelanosis: Presentation and Management

Idiopathic guttate hypomelanosis (IGH) is a benign, typically asymptomatic, acquired leukoderma characteristically affecting mature individuals. Although the etiopathogenesis is unclear, chronic sun exposure and senile degeneration are important triggers. Researchers have been engaged in a continuous effort to unveil the gray areas encompassing different aspects of IGH pathogenesis. IGH is a clinical diagnosis; however, histopathology and dermoscopy may aid in quetionable cases. Patients often seek cosmetic treatment. There has been no standard therapy for this condition. Newer treatment modalities range from topical agents to procedure-based therapies and have enhanced the therapeutic armamentarium. Here we discuss the pathogenesis, presentation, and management of IGH.

[Treatment of pigmentation disorders in association with systemic diseases]

Pigmentation disorders are a frequent skin problem and incorporate a broad spectrum of diseases, caused by an abnormal melanin pigmentation or also non-melanin pigmentation of the skin. Both hypermelanosis and hypomelanosis can be hereditary or acquired. This article summarizes the treatment approaches that are used in the majority of acquired pigmentation disorders of the skin. The following forms of hypermelanosis are addressed: lentiginosis, hyperpigmentation due to endocrine disorders or other systemic diseases, drug-induced hyperpigmentation. Acquired hypomelanoses include postinflammatory hypomelanosis, chemical depigmentation, idiopathic guttate hypomelanosis and punctate leucoderma. With reference to non-melanin pigmentation, the exogenous pigmentation due to chemicals, metals and drug exposure are discussed. The treatment is primarily based on finding the cause of the alterations to the pigment. The affected area, age and ethnic origin are also important factors. The spectrum of therapeutic options is broad: topical agents, chemical peeling, systemic agents, laser and light-based treatment. As some of these treatment procedures can have side effects, the availability of a protocol that contains information on the drug concentration, dose, parameters for laser treatment and the number of sessions is important. For every disorder the specific dermatological treatment is presented even when some pigmentation alterations that occur in association with systemic diseases, are cured by the treatment of the primary disease. Most diseases are exacerbated by exposure to UV light. Therefore, sun protection is recommended and a cosmetic coverage is indicated.

Acquired disorders with hypopigmentation: A clinical approach to diagnosis and treatment

Acquired hypopigmented skin changes are commonly encountered by dermatologists. Although hypopigmentation is often asymptomatic and benign, occasional serious and disabling conditions present with cutaneous hypopigmentation. A thorough history and physical examination, centered on disease distribution and morphologic findings, can aid in delineating the causes of acquired hypopigmented disorders. The second article in this 2-part continuing medical education series focuses on conditions with a hypopigmented phenotype. Early diagnosis and appropriate management of these disorders can improve a patient's quality of life, halt disease progression, and prevent irreversible disability.

Presentations, Signs of Activity, and Differential Diagnosis of Vitiligo

Vitiligo has a variety of presentations, including focal, acrofacial, segmental, and generalized forms. Thorough knowledge of these presentations is important to make the correct diagnosis. Signs of activity are important to recognize so that treatment is optimized. Clinical findings of confettilike depigmentation, trichrome and inflammatory vitiligo, and the Koebner phenomenon should alert the clinician that a patient's disease is likely to worsen. These patients may require systemic treatment to stabilize their disease. Many other skin disorders present with hypopigmentation or depigmentation and must be distinguished to determine the right diagnosis, advise the patient on prognosis, and prescribe the correct treatment.

Idiopathic Guttate Hypomelanosis: A Review of its Etiology, Pathogenesis, Findings, and Treatments

Idiopathic guttate hypomelanosis is a common acquired leukoderma characterized by multiple, discrete round or oval, porcelain-white macules on sun-exposed areas, especially on the extensor surface of forearms and pretibial areas. It usually affects individuals aged over 40 years and the likelihood of acquiring it increases with age. The exact pathogenesis remains controversial. However, there are several factors that are believed to be involved such as aging, ultraviolet exposure, trauma, genetic factors, autoimmunity, and local inhibition of melanogenesis. Despite the benign course of progression, many patients visit medical centers owing to cosmetic concerns and to confirm the natural course of idiopathic guttate hypomelanosis. Because there is no standard therapy for this condition, numerous medical and surgical treatments including intralesional corticosteroids, topical retinoids, topical calcineurin inhibitors, phenol peeling, cryotherapy, superficial dermabrasion, skin grafting, and ablative and non-ablative lasers have been tested with mixed results. This article will thoroughly review the etiology, pathogenesis, clinical presentations, histologic, dermoscopic, and ultrastructural findings, and the treatment of idiopathic guttate hypomelanosis.

Allelic Mutations of KITLG, Encoding KIT Ligand, Cause Asymmetric and Unilateral Hearing Loss and Waardenburg Syndrome Type 2

Linkage analysis combined with whole-exome sequencing in a large family with congenital and stable non-syndromic unilateral and asymmetric hearing loss (NS-UHL/AHL) revealed a heterozygous truncating mutation, c.286_303delinsT (p.Ser96Ter), in KITLG. This mutation co-segregated with NS-UHL/AHL as a dominant trait with reduced penetrance. By screening a panel of probands with NS-UHL/AHL, we found an additional mutation, c.200_202del (p.His67_Cys68delinsArg). In vitro studies revealed that the p.His67_Cys68delinsArg transmembrane isoform of KITLG is not detectable at the cell membrane, supporting pathogenicity. KITLG encodes a ligand for the KIT receptor. Also, KITLG-KIT signaling and MITF are suggested to mutually interact in melanocyte development. Because mutations in MITF are causative of Waardenburg syndrome type 2 (WS2), we screened KITLG in suspected WS2-affected probands. A heterozygous missense mutation, c.310C>G (p.Leu104Val), that segregated with WS2 was identified in a small family. In vitro studies revealed that the p.Leu104Val transmembrane isoform of KITLG is located at the cell membrane, as is wild-type KITLG. However, in culture media of transfected cells, the p.Leu104Val soluble isoform of KITLG was reduced, and no soluble p.His67_Cys68delinsArg and p.Ser96Ter KITLG could be detected. These data suggest that mutations in KITLG associated with NS-UHL/AHL have a loss-of-function effect. We speculate that the mechanism of the mutation underlying WS2 and leading to membrane incorporation and reduced secretion of KITLG occurs via a dominant-negative or gain-of-function effect. Our study unveils different phenotypes associated with KITLG, previously associated with pigmentation abnormalities, and will thereby improve the genetic counseling given to individuals with KITLG variants.

[Differential diagnostics of hypomelanoses]

Hypomelanoses of the skin encompass a wide spectrum of congenital and acquired alterations in melanin pigmentation. These diseases can be localized or universal. The pathobiology of cutaneous hypomelanoses is heterogeneous and includes defects in melanoblast migration from the neural crest to the epidermis, alterations in melanogenesis and melanin transfer to keratinocytes, and destruction of pigment cells by autoimmune and inflammatory processes. Importantly, some congenital forms of universal hypomelanoses are associated with involvement of internal organs (e.g., Hermansky-Pudlack or Chédiak-Higashi syndrome) and require interdisciplinary patient management. In recent years, significant progress has been made in our current understanding of the pathophysiology especially of vitiligo, thus, resulting in promising new treatment strategies. This disease being one of the most common forms of acquired hypomelanoses of the skin can now be treated in a guideline-oriented and evidence-based manner.