Photosensitivity disorders in children: part II

Algorithmic approach toward diagnosis of patients with congenital photosensitivity disorders and review of literature

The congenital photosensitivity disorders present as cutaneous signs and symptoms secondary to photosensitivity, extracutaneous manifestations, and a predisposition to malignancy. Diagnosis of these conditions mainly depend on clinical findings as the molecular analysis is not always feasible. A review of all the related articles collected after a thorough literature search using keywords, "congenital AND photosensitivity NOT acquired" and the individual diseases was done. A total of 264 articles were included in the review. An algorithm for diagnosis of the different congenital photosensitivity disorders based on the various clinical presentations has been proposed. An early suspicion and diagnosis of the different congenital photosensitivity disorders is the cornerstone behind prompt institution of prevention and treatment, and decreasing the associated morbidity.

Xeroderma pigmentosum group G with pellagroid rash: A rare presentation

Xeroderma pigmentosum (XP), a heterogeneous genodermatoses, has a variable clinical spectrum ranging from mild freckling and photosensitivity to severe skeletal and neurological abnormalities and cutaneous malignancies. Herein, we present the case of a 4-year-old boy with XP group G who presented with a pellagroid rash.

Xeroderma pigmentosum: case report

OBJECTIVE

The aim of this study was to describe the disease and treatment and to alert health professionals for the identification of signs and symptoms and the need for an early diagnosis in patients with xeroderma pigmentosum (XP).

CASE DESCRIPTION

An 8-year-old male patient was referred to the Joana de Gusmão Hospital (HIJG) in 2021 for evaluation and specialized care. Previously, the child was followed in his place of origin by oncologic and palliative care, where he was submitted to surgeries and chemotherapy. He was admitted to the HIJG using vismodegib, acitrein, tramadol, and solar protective measures. On physical examination, there were tumors and disseminated macular verrucous and ulcerated lesions. The imaging examination showed solid and expansive lesions on the face, and atelectasis and fibroscarring changes in the lung. The histopathological report proved the existence of melanocanthoma, carcinoma, and pyogenic granuloma. After the evaluation of the case, no surgery, chemotherapy, or radiotherapy was performed. It was decided to maintain the palliative treatment and to continue the use of tramadol for pain, and vismodegib and acitretin were used to control carcinomas and prophylactic measures.

COMMENTS

The XP is a rare disease of autosomal recessive inheritance whose mechanism comes from failure in the DNA repair by exposure to ultraviolet rays, resulting in lesions on the skin and mucous membranes. They start as sunburns and can progress to melanosis, areas with altered pigmentation, premature aging, poikiloderma, and areas of high risk for neoplasms.

Current concepts of photosensitivity in cutaneous lupus erythematosus

Cutaneous lupus erythematosus (CLE) represents a complex autoimmune disease with a broad phenotypic spectrum ranging from acute to chronic destructive cutaneous lesions. Patients with CLE exhibit high photosensitivity and ultraviolet (UV) irradiation can lead to systemic flares in systemic lupus erythematosus. However, the exact mechanisms how UV irradiation enhances cutaneous inflammation in lupus are not fully understood. Recently, new molecular mechanisms of UV-driven immune responses in CLE were identified, offering potential therapeutic approaches. Especially the induction of type I interferons, central cytokines in lupus pathogenesis which are released by various skin cells, have become the focus of current research. In this review, we describe current pathogenic concepts of photosensitivity in lupus erythematosus, including UV-driven activation of intracellular nucleic acid sensors, cellular cytokine production and immune cell activation. Furthermore, we discuss activated pathways contributing to enhanced apoptosis as well as intracellular translocation of autoantigens thereby promoting CLE upon UV light exposure.

Type I Interferon Induction in Cutaneous DNA Damage Syndromes

Type I interferons (IFNs) as part of the innate immune system have an outstanding importance as antiviral defense cytokines that stimulate innate and adaptive immune responses. Upon sensing of pattern recognition particles (PRPs) such as nucleic acids, IFN secretion is activated and induces the expression of interferon stimulated genes (ISGs). Uncontrolled constitutive activation of the type I IFN system can lead to autoinflammation and autoimmunity, which is observed in autoimmune disorders such as systemic lupus erythematodes and in monogenic interferonopathies. They are caused by mutations in genes which are involved in sensing or metabolism of intracellular nucleic acids and DNA repair. Many authors described mechanisms of type I IFN secretion upon increased DNA damage, including the formation of micronuclei, cytosolic chromatin fragments and destabilization of DNA binding proteins. Hereditary cutaneous DNA damage syndromes, which are caused by mutations in proteins of the DNA repair, share laboratory and clinical features also seen in autoimmune disorders and interferonopathies; hence a potential role of DNA-damage-induced type I IFN secretion seems likely. Here, we aim to summarize possible mechanisms of IFN induction in cutaneous DNA damage syndromes with defects in the DNA double-strand repair and nucleotide excision repair. We review recent publications referring to Ataxia teleangiectasia, Bloom syndrome, Rothmund–Thomson syndrome, Werner syndrome, Huriez syndrome, and Xeroderma pigmentosum. Furthermore, we aim to discuss the role of type I IFN in cancer and these syndromes.

Feeling the Burn: Phototoxicity and Photoallergy

An interaction between light's radiation and certain exogenous and endogenous substances can lead to the development of photoallergic and/or phototoxic dermatoses. Clinically, reactions may range from acute and self-limited to chronic and recurrent. Delays in diagnosis are not uncommon due to complex clinical presentations, broad differentials, and limited number of specialists who perform phototesting. Therefore, a critical understanding of these dermatoses is essential for accurate diagnosis and appropriate management. The epidemiology, light sources, mechanisms, clinical presentations, evaluation protocols, common culprits, treatments, key challenges, and future directions related to photoallergy and phototoxicity are reviewed herein.

Porphyrias: A clinically based approach

BACKGROUND

Porphyrias are a group of metabolic diseases, individually rare but with an important combined prevalence. Because of their pathological complexity and clinical heterogeneity, they present a challenging diagnosis. The present review aims to provide a clinically based approach to the recognition and treatment of these disorders.

METHODS

We carried out a search in PubMed, with the keyword "porphyria", for reviews published in English from 2010 until 2017.

RESULTS

The research yielded 196 papers, of which 64 were included in the final narrative review.

CONCLUSIONS

Porphyrias can be divided based on clinical presentation in acute neurovisceral, chronic cutaneous bullous, chronic cutaneous non-bullous and acute neurovisceral/chronic cutaneous bullous. Each individual porphyria presents a characteristic pattern of porphyrins in plasma, urine, stool and red blood cells. As such, diagnosis is easily obtained by following a simple diagnostic algorithm. Early recognition is key in managing these diseases. Neurovisceral porphyrias require acute support therapy and chronic eviction of precipitating factors. Cutaneous prophyrias, as photosensitivity disorders, rely on sunlight avoidance and, in some cases, specific therapeutic interventions. Given the rarity of these conditions, physician awareness is crucial.

Photosensitivity and photoprotection in patients with lupus erythematosus

Lupus erythematosus (LE) represents a spectrum of inflammatory autoimmune disease comprising varying clinical entities ranging from primary cutaneous to systemic disease. There is a clear relationship between ultraviolet irradiation (UVR) and the clinical manifestations of LE in both adult and pediatric populations. Although it has been established that UVR exacerbates pre-existing LE, it remains unclear whether UVR induces the development of the disease. This review serves to discuss effective photoprotective measures in LE and describe the pathogenic relationship of UVR and LE.

Recent Developments in the Diagnosis and Management of Photosensitive Disorders

Photodermatoses occur in males and females of all races and ages. Onset can be variable in timing and influenced by genetic and environmental factors. Photodermatoses are broadly classified as immunologically mediated, chemical- and drug-induced, photoaggravated, and genetic (defective DNA repair or chromosomal instability) diseases. Advances in the field have led to improved recognition and treatment of many photodermatoses. The purpose of this focused review is to provide an update on the diagnosis and management of a variety of photodermatoses, both common and less common, with review of recent updates in the literature pertaining to their diagnosis and management.

Cutaneous manifestations of nutritional deficiency

PURPOSE OF REVIEW

Childhood malnutrition is a major global health issue. It is often thought of as a developing world problem and therefore, underdiagnosed or misdiagnosed in developed countries. The delay in diagnosis and treatment can lead to increased morbidity and mortality. Cutaneous manifestations are often the initial presenting signs of nutritional deficiency. Early recognition is essential in timely initiation of the necessary interventions. This article will review pertinent cutaneous findings and systemic manifestations associated with common nutritional deficiencies.

RECENT FINDINGS

Malnutrition has historically been associated with poverty in developing countries. However, recent literatures suggest that the incidence of nutritional deficiencies continuous to rise among infants from developed countries, as a result of dietary restrictions because of perceived food allergies or intolerance. It is also an emerging finding in children with complicated medical problems.

SUMMARY

It is very important to raise awareness about cutaneous manifestations of nutritional deficiency as early and appropriate treatment results in excellent prognosis.

Understanding photodermatoses associated with defective DNA repair: Syndromes with cancer predisposition

Hereditary photodermatoses are a spectrum of rare photosensitive disorders that are often caused by genetic deficiency or malfunction of various components of the DNA repair pathway. This results clinically in extreme photosensitivity, with many syndromes exhibiting an increased risk of cutaneous malignancies. This review will focus specifically on the syndromes with malignant potential, including xeroderma pigmentosum, Bloom syndrome, and Rothmund-Thomson syndrome. The typical phenotypic findings of each disorder will be examined and contrasted, including noncutaneous identifiers to aid in diagnosis. The management of these patients will also be discussed. At this time, the mainstay of therapy remains strict photoprotection; however, genetic therapies are under investigation.

Facial involvement in genodermatoses

Facial involvement represents a characteristic feature of a wide range of genodermatoses. Specific facial findings often help point to the correct diagnosis, which improves counseling and management. In particular, this can facilitate the identification and treatment of associated extracutaneous disease. The highly visible nature of facial lesions in genodermatoses and facial birthmarks can result in stigmatization and frequently leads to particular concern in patients and their family members. It is therefore critical for dermatologists to be aware of the broad spectrum of facial manifestations in genetic skin disease, especially when these findings have important implications with regard to monitoring and treatment. In this contribution, facial involvement in genodermatoses is divided into five morphologic categories based on the most prominent feature: Papules, scaling, photosensitivity/findings associated with aging (eg, telangiectasias, atrophy, lentigines), blisters/erosions, and birthmarks. Hopefully, this will provide a practical and clinically useful approach to a large and diverse assortment of genetic skin conditions.

Cutaneous porphyrias part I: epidemiology, pathogenesis, presentation, diagnosis, and histopathology

The porphyrias are a group of disorders characterized by defects in the heme biosynthesis pathway. Many present with skin findings including photosensitivity, bullae, hypertrichosis, and scarring. Systemic symptoms may include abdominal pain, neuropsychiatric changes, anemia, and liver disease. With advances in DNA analysis, researchers are discovering the underlying genetic causes of the porphyrias, enabling family members to be tested for genetic mutations. Here we present a comprehensive review of porphyria focusing on those with cutaneous manifestations. In Part I, we have included the epidemiology, pathogenesis, presentation, diagnosis, and histopathology. Treatment and management options will be discussed in Part II.

Update on pediatric photosensitivity disorders

PURPOSE OF REVIEW

Although rare in the pediatric population, photosensitive dermatoses may begin prior to adulthood. The causes of photosensitivity are diverse, ranging from primary, immunologically mediated disorders of photosensitivity to inherited genetic or metabolic disorders. This review will highlight the key features of these disorders to familiarize the pediatric practitioner with their symptoms and any associated extracutaneous clinical or laboratory findings that may accompany them.

RECENT FINDINGS

New developments in the field of pediatric photosensitivity have been scant over recent years. While mechanisms of photosensitivity and genetic underpinnings associated with various conditions such as xeroderma pigmentosum continue to be uncovered, the literature on disorders of photosensitivity has been otherwise without many recent significant advances.

SUMMARY

Although the differential diagnosis of pediatric photosensitivity disorders is broad, it is often possible to establish the diagnosis by following an algorithmic approach. Once the correct diagnosis is rendered, this will guide any further workup that needs to be performed as well as specific management strategies.