Rosacea



Rosacea






Rosacea is a chronic skin disorder of diverse cutaneous manifestations associated with inflammation of the face.1 It occurs in about 10% of the population, most commonly in patients over 30 years of age and those with Fitzpatrick skin types I and II.2 Women are affected with cutaneous rosacea more frequently than men,3,4 but ocular rosacea affects both genders equally.3 Rosacea most commonly affects middle-aged adults, with a peak incidence between the ages of 40 and 59 years,3 but it may sometimes be seen in early childhood and old age.5 Approximately 30% to 40% of patients with rosacea report a family member with the condition.6

The diagnosis of rosacea is based on the clinical findings, but these are generally nonspecific, making the diagnosis difficult in many cases.7,8 In 2002, the National Rosacea Society Expert Committee on the Classification and Staging of Rosacea proposed four broad clinical subtypes of rosacea: erythematotelangiectatic, papulopustular, phymatous, and ocular.9,10

In erythematotelangiectatic rosacea, there are episodes of flushing of the central face, sometimes associated with telangiectasia. The redness also may involve the ears, scalp, neck, and chest, but the periocular skin is spared. Alcohol, spicy foods, exercise, cold or hot weather, and hot water may bring on these episodes.9 Papulopustular rosacea generally presents with erythema and flushing of the central portion of the face combined with intermittent or persistent episodes of small papules and pustules. As with the erythematotelangiectatic subtype, the periocular skin is usually spared.9 Phymatous rosacea is characterized by marked skin thickening and irregular nodularities that are most often seen on the nose (rhinophyma) and less frequently on the forehead, eyelids, and chin.9 In ocular rosacea, ophthalmic manifestations usually occur along with the cutaneous findings, but in some cases, they may precede them by many years.8,11 It is not clear if these different subtypes develop progressively or if they occur as discrete variants.12,13

Ocular rosacea usually presents with conjunctival hyperemia, epiphora, burning, itching, foreign body sensation, dry eyes, photophobia, blurred vision, conjunctival telangiectasia, eyelid blepharitis, and meibomian gland dysfunction.8,14 The findings of ocular rosacea in children are generally similar to those seen in adults.15 The skin findings are often absent in pediatric cases,16,17 but when present, they follow the ocular manifestations in about 55% of cases.18


Etiology and Pathophysiology

The etiology and pathophysiology of rosacea are not completely understood, but there is evidence to support a genetic predisposition. This includes the increased prevalence of rosacea in some northern European populations and the association of rosacea with autoimmune disorders.19 Gene array and polymerase chain reaction analyses indicate a defined gene profile for each of the different rosacea subtypes.12,20 Proposed factors that may be contributory to the development of rosacea include abnormal vascular reactivity, dysregulation of the innate immune system, increased susceptibility of sensory nerves to temperature changes or spicy foods, ethanol, exercise, UV radiation, Demodex overgrowth on the face or small intestinal bacterial overgrowth, and pilosebaceous unit abnormalities.4,13,21,22,23,24

Rosacea shows great variation in clinical manifestations suggesting a possible wide range of pathophysiological mechanisms.25 The major elements appear to be an augmentation of immune reaction and response, and neurovascular
dysregulation.25,26 There is an upregulation of genes involved in vasoregulation and neurogenic inflammation in all subtypes of the disease.27 The causes of transient flushing are poorly understood, but some evidence suggests it is associated with the release of antimicrobial peptides and proteases,28 neuropeptides,13 or transient receptor potential ion channels29 in the induction of erythema and vasodilation. The inflammatory infiltrate present in all four subtypes is not well characterized, but in early-onset rosacea, a lymphomonocytic infiltrate consisting primarily of CD3+ T cells, with CD20+ B cells, mast cells, and dendritic cells has been described.25,27,30






Environmental factors that are known to exacerbate the disease lead to the activation of proinflammatory products and innate immune responses.20,21 Cathelicidin, which has both vasoactive and proinflammatory actions, is elevated in the skin of patients with rosacea and has been implicated in its pathogenesis.21,28,31

In patients with ocular rosacea, the inflammatory basis of the disease is supported by elevated concentrations of interleukin-1a and 1b, tumor necrosis factor-alpha, and a greater activity of metalloproteinase-9 and collagenase-2 in tear fluids.32,33,34,35 Overexpression of toll-like receptor 2 on keratinocytes may explain enhanced inflammatory responses to environmental stimuli and may be a factor in the pathogenesis of rosacea.36 The inflammatory markers ICAM 1 and HLA-DR have also been observed to be overexpressed in conjunctival epithelial cells.37


Clinical Presentation

The symptoms of rosacea show episodes of exacerbations and remissions, but over time the disease usually progresses. While certain trigger factors such as sun exposure, extreme temperatures, alcohol, spicy foods, exercise, and emotional stress can worsen the symptoms, others, like smoking, appear to significantly reduce the risk of developing rosacea.3 Facial rosacea may present with little or no simultaneous eyelid involvement7 (Figure 109.1) More often, facial lesions include acne, sebaceous thickening with edematous papules and pustules, and thickening of the nose as rhinophymia (Figure 109.2). The eyelid inflammatory reaction results in meibomian gland dysfunction, chronic scarring of the gland orifices, and eyelid margin telangiectasias. This leads to tear film instability, epiphora, photophobia, keratitis, and blurred vision.38,39 Other common findings include blepharitis and collarettes around the eyelashes. Patients often experience recurrent hordeola and chalazia (Figure 109.3).7,17 Dry eye is a major finding in up to two-thirds of patients with ocular rosacea,37,40 and pinguecula, chronic cicatricial conjunctivitis, and fibrosis have also been reported.41,42,43

Corneal manifestations may be seen in up to 33% of patients.38,44 These can include superficial punctate keratitis on the lower third of the cornea and peripheral neovascularization with subepithelial infiltrates and can proceed to stromal ulceration, and even corneal perforation.45,46 Iritis, episcleritis, and scleritis are other potential ocular findings,7,47 and a case of spontaneous scleral perforation has been described.48


Differential Diagnosis

Systemic lupus erythematosus is a skin condition that can mimic rosacea. This is a chronic inflammatory disease that has protean clinical manifestations, which include malar erythema in approximately 50% of patients. The erythema may last for hours to days and often recurs, especially with sun exposure.49,50 Dermatomyositis is an inflammatory myopathy characterized by varying degrees of muscle weakness and skin erythema, but some patients lack muscular involvement and initially present only with skin manifestations. Macular violaceous erythema occurs most frequently in the seborrheic area of the face51 that might be

confused with the erythema seen in rosacea. Polymorphous light eruption is a common idiopathic photodermatosis with a higher prevalence in fair-skinned individuals,52 characterized by erythematous papules, papulovesicles, and plaques on exposed skin surfaces following sun exposure.53 Seborrheic dermatitis is a chronic skin disease characterized by a relapsing erythematous rash with well-demarcated patches, papules, or plaques seen most often on sebum-rich areas such as the face and scalp. Acne vulgaris is characterized by noninflammatory comedones and inflammatory papules, pustules, and nodules. It typically affects areas of skin with a high density of sebaceous glands such as the face, upper chest, and back.54 Other rare conditions that have been misdiagnosed as rosacea include carcinoid syndrome with flushing of the face, neck, and upper trunk55 and cutaneous lymphoma that can present with violaceous papules, plaques, and nodules on the face.56

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Nov 8, 2022 | Posted by in OPHTHALMOLOGY | Comments Off on Rosacea

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