WHAT IS COMORBIDITY?
Comorbidity is a concurrence of multiple diseases or disorders in association with a given disease, in this case, #psoriasis.
The patient with psoriasis has an increased risk of developing one or more of a number of other diseases/conditions that share many immunological features with psoriasis.
CHART 1: Comorbidities Associated with Psoriasis
Occular Inflammation –
1, 2, 3
Overall, ophthalmological manifestations occur in about 10% of the cases of psoriasis and include blepharitis, conjunctivitis, keratitis, xerophthalmia (a medical condition in which the eye fails to produce tears), corneal abscess, cataract, orbital myositis (inflammation of the eye muscles), symblepharon (adhesion of the eyelid to the eyeball), chorioretinopathy (detachment of the retina), uveitis and ectropion with trichiasis (inwardly growing eyelashes) and madarosis (loss of eyelashes) secondary to eyelid involvement. 1,2
Although the etiology of psoriasis and its association with ocular disease remains unknown, it has been suggested that activated neutrophils in peripheral blood may be responsible for the attacks of anterior uveitis associated with psoriatic arthritis. Uveitis tends to develop more often in patients with arthropathy or psoriasis pustulosa rather than the other forms of psoriasis. Psoriasis patients with uveitis tend to be older than those without psoriasis. 1,2
Uveitis is characterized by an intraocular inflammatory process resulting from various causes. Individual forms of uveitis may be differentiated as a function of the location of the inflammation within the eye, symmetry and continuity of the inflammation, associated complication and distribution of cells along the corneal endothelium. 1,2
The uvea is the mid-portion of the eye. Its anterior portion includes the iris and the ciliary muscle, and its posterior portion consists of the choroid. Anterior uveitis or iritis is the inflammation of the anterior uveal tract. When the adjacent ciliary body is also affected, the process is known as iridocyclitis. Anterior uveitis is four times more common than posterior uveitis.
Uveitis can be divided into four main subgroups according to the etiology of the inflammation – infectious disease, immune-mediated disease, syndromes limited to the eyes or idiopathic forms. Of the patients with uveitis, around 40% of cases are secondary to an immune-mediated disease; around 30% of the cases of uveitis do not fit into any well-defined etiology. 1,2
Uveitis may occur in 7-20% of the patients with psoriasis. In a cross-sectional study researchers found a prevalence of uveitis of 2% in patients with psoriasis irrespective of the severity of the dermatosis. The association between uveitis and chronic plaque psoriasis has also been found, and in these patients uveitis tends to be bilateral affecting both eyes), prolonged and more severe. Uveitis, particularly anterior uveitis, has also been associated with the arthropathic form of the disease and approximately 7% of the patients with psoriatic arthritis may develop uveitis. Some cases of uveitis have been reported to occur even before psoriatic skin disease, and uveitis has been reported as the first presenting sign of Spondyloarthropathies (SpAs – a family of long-term (chronic) diseases of joints) in up to 11.4% of cases. The severity of ocular inflammation does not necessarily correlate with extent of joint findings but may correlate with skin disease. 1,2
Conjunctivitis is a commonly occurring eye condition that can be caused by psoriasis, but it is more commonly due to allergies, bacterial infection, or viral infection. The most common presentation is generalized conjunctival injection with mild photophobia, gritty discomfort, and possible discharge. Thick purulent (pus-like) discharge is a hallmark of bacterial infection and watery discharge is characteristic of viral infections. Increased rates of obstructive meibomian (tarsal – sebaceous gland at the rim of the eyelids) dysfunction were noted in psoriatic patients. Published articles have suggested conjunctivitis prevalence rates in psoriasis patients as high as 64.5%.4
Dry eye (Keratoconjunctivitis sicca – Dry Eye Syndrome) has been cited at a prevalence rate of 2.7% of psoriatic arthritis patients. Studies have suggested prevalence rates of dry eyes as high as 18.00% of psoriasis patients.4
Facial psoriasis can of course present on the eyebrows and on the eyelids.
Facial Psoriasis – Before Facial Psoriasis – After
When psoriasis affects eyelids or eyelashes, these may become covered with fine plaques and the rims of the eyelids may become red and crusty. If the rims of the eyelids are irritated for long periods of time, the rims of the lids may turn up or down (Ectropion). If the rims turn down, the lashes have a tendency to rub against the surface of the eye and cause further irritation and possibly damage to the surface of the eye.
Psoriatic eye manifestations, uveitis in particular, can lead to serious consequences, including vision loss. It is important at the first sign of occular redness, weeping, blurred vision, for psoriasis sufferers to see their Practitioner immediately, as they may need to be referred to an Ophthalmologist depending upon the severity of the symptoms.
- Arzu K?l?ç, Seray Cakmak; PSORIASIS AND COMORBIDITIES; EMJ Dermatol. 2013;1:78-85.
- Howa Yeung et al.;Psoriasis Severity and the Prevalence of Major Medical Comorbidity – A Population-Based Study; JAMA Dermatol. 2013;149(10):1173-1179. doi:10.1001/jamadermatol.2013.5015
- Aurangabadkar SJ. Comorbidities in psoriasis. Indian J Dermatol Venereol Leprol 2013;79, Suppl S1:10-7
- Shiu-chung Au et al.; Psoriatic Eye Manifestations; FALL 2011; psoriasis forum, Vol. 17, No. 3; https://www.psoriasis.org/files/pdfs/forum/Psoriatic-Eye-Manifestations-Forum_Fall_11_WEB.pdf
- Naiara Abreu de Azevedo Fraga et al.; Psoriasis and uveitis: a literature review; An Bras Dermatol. 2012;87(6):877-83. http://www.scielo.br/pdf/abd/v87n6/v87n6a09.pdf