Whether through infection or other causes, this balance can be upset and autoreactive T cells allowed to proliferate and migrate to the eye. Upon entry to the eye, these cells may be returned to an inducible Treg state by the presence of IL-10 and TGF-beta from microglia. Failure of this mechanism leads to neutrophil and other leukocyte recruitment from the peripheral blood through IL-17 secretion. Tissue destruction is mediated by non-specific macrophage activation and the resulting cytokine cascades. Serum TNF-α is significantly elevated in cases while IL-6 and IL-8 are present in significantly higher quantities in the aqueous humour in patients with both quiescent and active uveitis. These are inflammatory markers that non-specifically activate local macrophages causing tissue damage. Genetic factors
The cause of non-infectious uveitis is unknown but there are some strong genetic factors that predispose disease onset including HLA-B27 and the PTPN22 genotype. Infectious agents
Recent evidence has pointed to reactivation of herpes simplex, varicella zoster and other viruses as important causes of developing what was previously described as idiopathic anterior uveitis. Bacterial infection is another significant contributing factor in developing uveitis. Diagnosis
Diagnosis includes dilated fundus examination to rule out posterior uveitis, which presents with white spots across the retina along with retinitis and vasculitis. Laboratory testing is usually used to diagnose specific underlying diseases, including rheumatologic tests (e.g. antinuclear antibody, rheumatoid factor) and serology for infectious diseases (Syphilis, Toxoplasmosis, Tuberculosis). Major histocompatibility antigen testing may be performed to investigate genetic susceptibility to uveitis.
Confluent and reticulated papillomatosis of Gougerot and Carteaud is an uncommon but distinctive acquired ichthyosiform dermatosis characterized by persistent dark, scaly, papules and plaques that tend to be localized predominantly on the central trunk. Eponym
Henri Gougerot and Alexandre Carteaud originally described the condition in 1927. The cause remains unknown, but the observation that the condition may clear with Minocycline turned attention to an infectious agent. Actinomycete Dietzia strain X was isolated from one individual. Other antibiotics found useful include azithromycin, fusidic acid, clarithromycin, erythromycin, tetracycline and cefdinir. See also
Ichthyosis
Acquired ichthyosis
List of cutaneous conditions

References


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