Evidence that thalidomide modifies the immune response of patients suffering from actinic prurigo

Actinic prurigo

Actinic prurigo is a chronic photodermatosis with onset in childhood or before 20 years of age. It is most prevalent in Amerindians and Latin American mestizos, although it has been reported worldwide. Patients present with photodistributed, erythematous excoriated papules, cheilitis, and conjunctivitis. There is strong association with human leukocyte antigen DR4, especially the DRB1*0407 subtype. Treatment consists of photoprotection and the use of thalidomide.

Actinic prurigo: a case-control study of risk factors

BACKGROUND

Actinic prurigo (AP) is an idiopathic photodermatosis that usually onsets during childhood and predominates in women. It is characterized by the symmetrical involvement of sun-exposed areas of the skin, lips, and conjunctiva.

OBJECTIVES

This study aimed to analyze the risk factors associated with AP using a case-control design.

METHODS

All patients diagnosed with AP during 1990-2006 at Dr. Manuel Gea González General Hospital in Mexico City were included. Respective controls were recruited. Race, demographic, geographic, socioeconomic, environmental, clinical, and nutritional risk factors were assessed.

RESULTS

A total of 132 persons were enrolled. These included 44 cases and two control groups comprising, respectively, dermatology and non-dermatology outpatients without AP or any autoimmune disease. Distribution by gender, age, place of birth, place of residence, and economic status did not differ significantly among the three groups. A total of 256 variables were analyzed. Only 19 variables were found to be statistically significant (P < 0.05). These were: use of a boiler; use of firewood; car ownership; use of earthenware; mixed material housing; socioeconomic level 1; sun exposure; use of soap; lemon consumption; use of moisturizing hair cream; living with pets in the house; living with farm animals; age; having a family member with AP; having had surgery; having had trauma; having been hospitalized; use of oral medication; and use of herbal medication. Of 40 macro- and micronutrients analyzed, 11 were found to have statistically significant effects (P < 0.05).

CONCLUSIONS

Multiple epidemiologic, geographic, clinical, and immunologic factors are involved in the etiology of AP. This study proposes a clear line for research directed at specific risk factors that refer to an individual's clinical, allergic, health, and socioeconomic status. Further study should also investigate the etiologic role of diet in AP and the molecular mechanisms behind the development of AP to establish whether AP is caused by exposure to polycyclic aromatic hydrocarbons.

Photodermatoses: classification, evaluation and management

Photodermatoses are skin disorders induced or exacerbated by light. They can be broadly classified into four groups: (i) immunologically mediated photodermatoses (idioapathic); (ii) drug- and chemical-induced photosensitivity; (iii) defective DNA repair disorders; and (iv) photoaggravated dermatoses. The exact pathomechanism of those diverse skin reactions to light radiation remains unclear. Immunologically mediated photodermatoses are the most common dermatoses among all photosesnsitive disorders. The management of photodermatoses starts with clinical recognition of characteristic lesions localized predominantly in light exposed skin. Detailed history-taking, phototesting and photopatch testing are required to establish a correct diagnosis, especially if patients present in disease-free intervals. Classification and short description of distinctive clinical features of most common photodermatoses, several practical aspects of evaluation and management of the patient with photosensitivity will be outlined.

Thalidomide has both anti-inflammatory and regulatory effects in Behcet's disease

Thalidomide is shown to be an effective treatment for mucocutaneous symptoms of Behcet's disease (BD). In this study, the effects of thalidomide on peripheral blood mononuclear cells were investigated ex vivo. In an open prospective study, ten patients were given 200 mg/day thalidomide for 12 weeks and cluster of differentiation 4 (CD4), CD8, CD11a, CD11b, CD16, CD18, CD28, CD44, CD45RO, CD45RA, CD56, CD120a and gammadelta+ T cells were analysed with flow cytometry at 0, 3, 7, 30 and 90 days. Two patients were excluded from the analysis for attacks of uveitis within the first 2 weeks. At day 7, tumour necrosis factor-alpha (TNF-alpha) receptor+ (CD120a; 12% vs 5%), CD8/CD11b+ (12% vs 6%) and CD16/CD56+ (16% vs 9%) cells decreased in BD patients compared to day 0. On the other hand, CD4+CD45RO+ T cells (24% vs 34%) at day 30 and gammadelta+ T cells (11% vs 21%) at day 90 increased after treatment. These results suggest that thalidomide tends to decrease TNF-alpha receptor levels, CD8/CD11b+ T cells and natural killer cells in early treatment and increases CD4+CD45RO+ memory T and gammadelta+ T cells later in BD.

Nichthereditäre Photodermatosen im Kindesalter

Non-hereditary photodermatoses with well-known trigger factors and idiopathic light eruptions occur quite frequently during childhood and are at least temporarily associated with a marked impairment of quality of life in affected patients and their parents. Thus, it is crucial that the involved specialties are familiar with acquired UV-associated disorders in order to guarantee a quick diagnosis and effective therapy. Additionally, the recurrence of photodermatoses associated with potentially severe long-term complications has to be prevented. This requires a stringent prophylaxis that can only succeed after age-adapted instruction of the patient and parents.

Successful thalidomide therapy for actinic prurigo in a European woman

Actinic prurigo is a rare, often difficult-to-treat, idiopathic photodermatosis. Actinic prurigo is divided into a hereditary form appearing in the Native American population and a sporadic form occurring in non-Native Americans. We present a 28-year-old Caucasian woman who developed typical clinical signs and symptoms of actinic prurigo, just as had her mother and grandmother. The patient and her mother were HLA-A24 and HLA-DR 4 with the subtype HLA-DRB1*0408. Based on clinical symptoms and the HLA pattern, the diagnosis of actinic prurigo was made. Treatment with thalidomide led to resolution of the disease. This case report of a Caucasian woman suffering from a hereditary form of actinic prurigo questions the established classification of actinic prurigo into a hereditary Native American form and a sporadic form occurring in the non-Native American population.