Successful treatment of actinic prurigo with baricitinib in an 8-year-old child: A case report.

Actinic prurigo is a rare photodermatosis characterized by pruritic papulonodular lesions. Treatment is challenging, especially in children, as sun protection strategies need to be rigorously implemented and symptoms often persist throughout the year. Herein, we present a case of actinic prurigo in an 8-year-old patient with rapid and successful relief with baricitinib.

Actinic conjunctivitis and its relationship with prurigo in an indigenous population from the Highlands of Chiapas, Mexico.

PURPOSE: Actinic conjunctivitis (AC), along with cheilitis (AChe), is part of the clinical spectrum of actinic prurigo (AP), a rare photo dermatosis that affects high-risk populations. We analyzed the clinical manifestations and onset of actinic conjunctivitis (AC), and its relationship with prurigo (AP) in a susceptible population. METHODS: This prospective observational cohort study was performed on Indigenous populations from the highlands of Chiapas, Mexico. Thorough dermatological and ophthalmological examinations were performed in patients attending a primary health care center. The clinical features, labor and environmental factors, onset timing, and clinical staging of AC and AP were analyzed. RESULTS: Of the 2913 patients studied, 54 patients (108 eyes) (1.8%) had AC, and 14 patients (25.9%) had AP. The mean age at diagnosis was 36.18 ± 18.52 years (6-70 years). The mean residential altitude was 1884 ± 434.2 m above sea level. Mean self-reported sun exposure was 5.14 ± 3.1 h a day (0.5-12 h). A total of 90.7% reported exposure to biomass fuels during cooking, and 50% to farm animals. AC was the sole manifestation in 70% of the cases. All patients had nasal and temporal photo-exposed conjunctiva. Among the eyes, 12.9% were classified as stage-1, 64.8% as stage-2, and 22.2% stage-3. A total of 83.3% of the patients had hyperpigmented lesions, and 35.1% had evaporative dry eye disease. CONCLUSIONS: AC may be the initial or sole manifestation of AP. Most AC cases (87%) were initially observed at the advanced stages of the disease. Although solar exposure was not associated with late AC stages, a positive association was found with farm animal exposure. Evaporative dry eye associated with meibomian gland dysfunction has not been previously reported in patients with AC.

Variable Presentations of Photodermatoses - A Case Series.

Photodermatoses represent a broad spectrum of skin diseases caused because of exposure to ultraviolet radiation. It is categorized mainly as idiopathic photosensitive disorders, drug or chemical induced photosensitivity reactions, DNA repair-deficiency photodermatoses and photoaggravated dermatoses. Despite being under the photodermatoses umbrella, the pathophysiology of each type of photodermatoses varies. We reported 4 cases of photodermatoses including azathioprine induced pellagra, adult onset actinic prurigo, and photoallergic contact dermatitis due to NSAIDs and cutting fluids. Photoprotection with the usage of photoprotective clothing, broad-spectrum sunscreen application and avoidance of photosensitizing drugs and chemicals are crucial.

The Immunogenetics of Photodermatoses.

Photodermatosis is an abnormal skin inflammatory reaction to light. The major classifications of photodermatoses are idiopathic photodermatoses, photodermatoses due to exogenous or endogenous agents, photo-exacerbated dermatoses, and photosensitive genodermatoses. In this chapter, we focus on idiopathic photodermatoses and drug-related photodermatoses and emphasize on the epidemiology and immunogenetic backgrounds. Idiopathic photodermatoses, a spectrum of diseases with abnormal responses to ultraviolet radiation (UVR), include polymorphous light eruption, actinic prurigo, hydroa vacciniforme, chronic actinic dermatitis, and solar urticaria. Young people are more susceptible to most idiopathic photodermatoses except for chronic actinic dermatitis. Interestingly, idiopathic photodermatoses exhibit different characteristics between Caucasians and Asians. For example, the average age of Asian actinic prurigo patients is older than that of Caucasians in which genetic backgrounds or Fitzpatrick skin type might play a role. Drug-induced photodermatoses can be classified into phototoxic and photoallergic drug reactions. Certain drug-induced photodermatoses may mimic other dermatoses. For instance, drug-induced lupus erythematosus (LE) should be considered if an old man is diagnosed with LE but had a poor response to standard treatments.

Value of the toluidine blue test as an aid to determine the biopsy site in actinic prurigo cheilitis.

Actinic prurigo (AP) is a type of photodermatosis that primarily affects the Latin American mestizo population. Histologically, AP cheilitis exhibits acanthosis with spongiosis and vacuolation of the basal cell layer overlying a dense lymphocytic inflammatory infiltrate that forms well-defined lymphoid follicles. Toluidine blue is a thiazide, acidophilic, and metachromatic dye used in vivo to selectively stain the acidic components of tissues such as sulfates, carboxylates, and phosphate radicals that are incorporated into DNA and RNA. It is necessary to develop a method that allows detecting, on clinical grounds the area of the lesion in which it is more feasible to find such structures. Thus to increase the sensitivity of the biopsy, in AP cheilitis to accurately identify where the lymphoid follicles reside, based on the higher concentration of DNA in such structures and thus confirm the diagnosis. In this study, staining was positive in 85% of patients with AP cheilitis, in 14 of whom 82% lymphoid follicles were observed by histopathology. One of the pathologist's problems in establishing the diagnosis of AP is that the main histopathological characteristics are not always identified in the submitted samples because it is not easy to clinically identify the most representative site of the lesion selected for performing a biopsy. Based on our results, we propose using toluidine blue as an auxiliary method to choose a tissue sample to facilitate the diagnosis and allow clinicians to make clinical correlations between the histopathological and therapeutic findings.

Value of the toluidine blue test as an aid to determine the biopsy site in actinic prurigo cheilitis

Actinic prurigo (AP) is a type of photodermatosis that primarily affects the Latin American mestizo population. Histologically, AP cheilitis exhibits acanthosis with spongiosis and vacuolation of the basal cell layer overlying a dense lymphocytic inflammatory infiltrate that forms well-defined lymphoid follicles. Toluidine blue is a thiazide, acidophilic, and metachromatic dye used in vivo to selectively stain the acidic components of tissues such as sulfates, carboxylates, and phosphate radicals that are incorporated into DNA and RNA. It is necessary to develop a method that allows detecting, on clinical grounds the area of the lesion in which it is more feasible to find such structures. Thus to increase the sensitivity of the biopsy, in AP cheilitis to accurately identify where the lymphoid follicles reside, based on the higher concentration of DNA in such structures and thus confirm the diagnosis. In this study, staining was positive in 85% of patients with AP cheilitis, in 14 of whom 82% lymphoid follicles were observed by histopathology. One of the pathologist's problems in establishing the diagnosis of AP is that the main histopathological characteristics are not always identified in the submitted samples because it is not easy to clinically identify the most representative site of the lesion selected for performing a biopsy. Based on our results, we propose using toluidine blue as an auxiliary method to choose a tissue sample to facilitate the diagnosis and allow clinicians to make clinical correlations between the histopathological and therapeutic findings.

Clearance of pediatric actinic prurigo with dupilumab.

Actinic prurigo is a rare, idiopathic chronic photodermatosis of childhood characterized by excoriated papules, nodules, and plaques in sun-exposed areas. It is notoriously difficult to treat. The disorder involves a type IV hypersensitivity reaction driven by both Th1 and Th2 inflammatory pathways, the latter of which leads to secretion of IL-4, IL-5, IL-13, and production of B cells, IgE, and IgG4. Dupilumab, an IL-4 receptor antagonist, disrupts the Th2 pathway. We present a pediatric patient with severe, recalcitrant actinic prurigo who achieved rapid and sustained clearance with dupilumab.

Epidermal Langerhans cells resistance to solar-simulated radiation in actinic prurigo patients with low minimal erythema dose.

BACKGROUND: Actinic prurigo is a chronic photodermatosis of unclear pathogenesis. Epidermal Langerhans cell resistance to migration after ultraviolet radiation exposure has been proposed as a possible mechanism, as occurs in polymorphic light eruption patients. The purpose of this study was to evaluate the effect of solar-simulated radiation (SSR) on epidermal Langerhans cells in the uninvolved skin of actinic prurigo patients. PATIENTS AND METHODS: Fifteen patients with actinic prurigo participated in the study. A biopsy from the uninvolved and unirradiated skin of the left buttock was performed, and another from the uninvolved skin of the right buttock, 72 hours after exposure to two MEDs of SSR. Immunohistochemistry staining was used to identify Langerhans cells (CD1a) in all samples. RESULTS: In actinic prurigo patients with normal MED, there was a significant decrease in the number of epidermal Langerhans cells on the buttock skin exposed to two MED of SSR compared with the unirradiated buttock skin (P = .02 and .035 respectively). On the contrary, in patients with low MED there were no significant differences in the number of epidermal Langerhans cells between irradiated and unirradiated skin (P = .39). CONCLUSION: Epidermal Langerhans cells migration after ultraviolet radiation exposure is decreased in actinic prurigo patients with low MED as has been reported in PLE patients, especially, those with low MED or positive UVB provocation tests. Langerhans cells resistance could be part of a common pathogenic mechanism in these two photodermatoses.

Thalidomide: An option for the pediatric patient with actinic prurigo.

Actinic prurigo (AP) is an immune-mediated photodermatosis that usually starts in childhood and is predominant among American indigenous and mestizo communities. In adults with AP, thalidomide is the treatment of choice; however, there is little information on its use in pediatric patients. We report the case of a 10-year-old girl with AP treated successfully with thalidomide.

Phototherapy in the Evaluation and Management of Photodermatoses.

Ultraviolet light (UV) and visible light are important components in the diagnosis of photodermatoses, and UV has the unique ability to also be used to manage photodermatoses. Phototesting, provocative light testing, and photopatch testing can provide important information in diagnosing patients with photodermatoses; phototesting can be used to determine the starting dose for phototherapy in these patients. Once photosensitivity is established, narrowband UVB and UVA1 therapy have helped to improve the quality of life of photosensitive patients, such as those with polymorphous light eruption, chronic actinic dermatitis, and solar urticaria.

Expression of E-cadherin, syndecan 1, Ki-67, and maintenance minichromosome 3 in tissue lesions of actinic prurigo obtained by incisional biopsy.

Actinic prurigo (AP) is an idiopathic photodermatosis; the initial manifestations usually occur during the first decades of life but can appear at any age. Cases are usually diagnosed late once the lesions have exacerbated; due to the extensive involvement of the vermilion border and the etiology, it has been confused with and related to a potentially malignant process. Syndecan-1 and E-cadherin were positive in the epidermis, with moderate-to-intense staining in 100% of samples. Ki67 and MCM3 were expressed in the lower third of the epidermis and showed greater immunolabeling in samples that contained lymphoid follicles (Ki 67: epidermis [17.7% ± 6.79%] and dermis [7.73% ± 6.69%]; MCM3: epidermis [22.92% ± 10.12%] and dermis [6.13% ± 6.27%]). In conclusión AP is a disease in which there is no evidence that the lesions are potentially cancerous. AP cheilitis should not be confused with actinic cheilitis because they are separate entities.

Thalidomide for the treatment of chronic refractory pruritus.

Pruritus is a common and often times difficult to treat symptom in many dermatologic and systemic diseases. For pruritus with an inflammatory or autoimmune origin, therapies such as topical corticosteroids and antihistamines are often initiated. However, in the case that these and additional systemic therapies are ineffective, thalidomide, an immunomodulator and neuromodulator, may be a useful alternative treatment. Considerable relief of chronic pruritus has been demonstrated with thalidomide in case reports, case series, and controlled trials. Double-blind controlled studies demonstrated thalidomide's efficacy as an antipruritic agent in patients with uremic pruritus, primary biliary cirrhosis, and prurigo nodularis. In case reports, case series, and open-label trials, thalidomide significantly reduced pruritus associated with conditions such as actinic prurigo and paraneoplastic pruritus. Because of variations in study design and evaluation of antipruritic effect, it is difficult to fully understand thalidomide's role based on the evidence described to date in the medical literature. In this review, we provide an overview of the reported findings and evaluate thalidomide's utility in managing refractory pruritus in the context of its adverse risk profile. We propose that thalidomide can be an alternative or combination antipruritic treatment for patients who do not obtain enough relief from conservative therapy.

Prurigo actínico: tratamiento con tacrolimus. Respuesta favorable en dos pacientes pediátricos / Actinic prurigo: treatment with tacrolimus: Favorable response in two pediatric patients

El prurigo actínico es una foto-dermatosis crónica e idiopática, que afecta principalmente a la población de origen mestizo y a la piel foto-expuesta. La enfermedad se distingue por un franco polimorfismo clínico, presentando un 45% de compromiso ocular y entre un 30 a 70% de la semi-mucosa labial. Para su tratamiento se indican: fotoprotección, antihistamínicos, corticoides y talidomida, entre otros. Comunicamos dos pacientes con diagnóstico de prurigo actínico, que realizaron tratamiento con tacrolimus tópico, observándose buena respuesta clínica.

Actinic prurigo is a chronic idiopathic photo dermatosis which is more common in high-altitude living people, mainly in indigenous descendants, affecting skin exposed to light. The disease is characterized by clinical polymorphism, involving 45% ocular manifestations and between 30-70% of labial semi mucous. Treatment is based on: photo protection, antihistamines, corticosteroids, thalidomide, among others. We present two patients diagnosed with actinic prurigo who performed treatment with topical tacrolimus, showing a successful clinical response.