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.

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.

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 of the lip: Two case reports

Actinic prurigo is a photodermatosis that can affect the skin, conjunctiva and lips. It is caused by an abnormal reaction to sunlight and is more common in high-altitude living people, mainly in indigenous descendants. The diagnosis of actinic prurigo can be challenging, mainly when lip lesions are the only manifestation, which is not a common clinical presentation. The aim of this article is to report two cases of actinic prurigo showing only lip lesions. The patients were Afro-American and were unaware of possible Indian ancestry. Clinical exam, photographs, videoroscopy examination and biopsy were performed, and the diagnosis of actinic prurigo was established. Topical corticosteroid and lip balm with ultraviolet protection were prescribed with excellent results. The relevance of this report is to show that although some patients may not demonstrate the classical clinical presentation of actinic prurigo, the associated clinical and histological exams are determinants for the correct diagnosis and successful treatment of this disease.

Evaluation of patients with photodermatoses

The systematic evaluation of photosensitive patients involves a comprehensive history, physical examination, phototesting, and, if necessary, photopatch testing and laboratory evaluation. Polymorphous light eruption, chronic actinic dermatitis, solar urticaria, and photosensitivity secondary to systemic medications are the most commonly encountered photodermatoses in dermatology clinics worldwide.

Chlamydia trachomatis Infection and Photosensitive Dermatoses

BACKGROUND

Photosensitivity to Chlamydia trachomatis has been described in almost 50% of chronic cases of lymphogranuloma venereum (LGV) caused by L1, L2 or L3 serovars. Photosensitivity in non LGV strains of C trachomatis has not been studied. We studied the association of various photosensitive dermatoses with C trachomatis infection in non LGV cases.

METHODS

Sera of all the cases of photosensitivity, melasma, chronic actinic dermatitis (CAD), polymorphic light eruption (PLE), actinic prurigo (AP) and rosacea were tested for the presence of IgM, IgG and IgA antibodies to C trachomatis by ELISA method. The results were compared with 30 healthy controls.

RESULT

Seventeen (25.53%) of 57 cases of photosensitivity as against two (6.67%) controls were seropositive for IgM/IgG/IgA antibodies, a statistically significant difference (χ(2) 6.18, p 0.013). Similarly, significantly higher seropositivity was observed in 12 (25.53%) of 47 cases of melasma (χ(2) 4.38, p 0.0363) and six (46.15%) of 13 cases with CAD (χ(2) 6.91, p 0.0086). Although higher proportion of patients of rosacea [five (31.25%) of 16 cases] and PLE [four (25.0%) of 16 cases] were seropositive, the difference was not statistically significant (χ(2) 3.23, p >0.05, OR 6.36, CI 95% 0 to 48 and χ(2) 3.09, p 0.078, OR 4.67, CI 95% 5 to 41 respectively). There was no association of AP.

CONCLUSION

The observations suggest that C trachomatis infection in non LGV cases is an important cause of PS, melasma and CAD. It appears to be an important cause of rosacea and PLE. We recommend that all cases of photosensitivity, melasma, CAD, PMLE and rosacea and their spouses/sexual contacts be investigated for C trachomatis infection.