Psoriasis overview: Difference between revisions
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==Overview== | ==Overview== | ||
Psoriasis is a [[systemic]], [[immune-mediated disease]], characterized by [[inflammation]] of the [[skin]] and [[joints]]. It commonly causes red [[Scaling skin|scaly]] patches to appear on the [[skin]]. The scaly patches caused by psoriasis, called psoriatic plaques, are areas of [[inflammation]] and excessive [[skin]] production. [[Skin]] rapidly accumulates at these sites and takes a silvery-white appearance. Plaques frequently occur on the skin of the [[Elbow-joint|elbows]] and [[knee]]s, but can affect any area including the [[scalp]] and [[sex organ|genitals]]. Psoriasis is hypothesized to be [[immune-mediated disease|immune-mediated]] and is not [[contagious]].The [[disease|disorder]] is a [[chronic (medicine)|chronic]] recurring condition which varies in severity from minor localized patches to complete body coverage. [[Nail (anatomy)|Fingernails]] and [[toenails]] are frequently affected ([[psoriatic]] [[Nail Changes|nail]] [[dystrophy]]). Psoriasis can also cause [[Arthritis|inflammation of the joints]], which is known as [[psoriatic arthritis]] and 10-15% of people with psoriasis have psoriatic arthritis. The International Psoriasis Council, identifies four main forms of psoriasis which are [[Psoriasis classification#Classification|plaque-type psoriasis]], [[Psoriasis classification#Classification|guttate psoriasis]], [[Psoriasis classification#Classification|generalized pustular psoriasis (GPP)]] and [[Psoriasis classification#Classification|erythrodermic psoriasis]]. The [[pathophysiology]] consists of interactions between [[Cytokine|cytokines]], [[Dendritic cell|dendritic cells]] and [[T lymphocytes]] (particularly [[Th1]] and [[Th17]]). Psoriasis must be differentiated from other diseases that cause [[erythematous]], scaly [[Rash erythematous|rash]] such as [[Cutaneous T cell lymphoma]]/[[mycosis fungoides]], [[pityriasis rosea]], [[pityriasis rubra pilaris]], [[pityriasis lichenoides chronica]], [[nummular dermatitis]], [[secondary syphilis]], [[bowen’s disease]], [[exanthematous pustulosis]], [[Lichen planus|hypertrophic lichen planus]], Sneddon–Wilkinson disease, [[Parapsoriasis|small plaque parapsoriasis]], [[intertrigo]], [[langerhans cell histiocytosis]], [[dyshidrotic dermatitis]], [[tinea manuum]]/pedum/[[Tinea capitis|capitis]] and [[seborrheic dermatitis]]. The [[prevalence]] of psoriasis is estimated to be 500 per 100,000 cases to 4600 per 100,000 cases annually. The mainstay of therapy for psoriasis is [[topical]] agents applied directly onto the lesions. [[Topical]] agents include [[Corticosteroid|corticosteroids]], [[vitamin D]] analogues, [[tar]], [[anthralin]], [[tazarotene]], [[calcineurin]] inhibitors and [[aloe vera]] extracts. Systemic therapy may also be used which includes [[Immunosuppresive drug|immunosupressants]] to counter act the disease process. | Psoriasis is a [[systemic]], [[immune-mediated disease]], characterized by [[inflammation]] of the [[skin]] and [[joints]]. It commonly causes red [[Scaling skin|scaly]] patches to appear on the [[skin]]. The scaly patches caused by psoriasis, called psoriatic plaques, are areas of [[inflammation]] and excessive [[skin]] production. [[Skin]] rapidly accumulates at these sites and takes a silvery-white appearance. Plaques frequently occur on the skin of the [[Elbow-joint|elbows]] and [[knee]]s, but can affect any area including the [[scalp]] and [[sex organ|genitals]]. Psoriasis is hypothesized to be [[immune-mediated disease|immune-mediated]] and is not [[contagious]].The [[disease|disorder]] is a [[chronic (medicine)|chronic]] recurring condition which varies in severity from minor localized patches to complete body coverage. [[Nail (anatomy)|Fingernails]] and [[toenails]] are frequently affected ([[psoriatic]] [[Nail Changes|nail]] [[dystrophy]]). Psoriasis can also cause [[Arthritis|inflammation of the joints]], which is known as [[psoriatic arthritis]] and 10-15% of people with psoriasis have psoriatic arthritis. The International Psoriasis Council, identifies four main forms of psoriasis which are [[Psoriasis classification#Classification|plaque-type psoriasis]], [[Psoriasis classification#Classification|guttate psoriasis]], [[Psoriasis classification#Classification|generalized pustular psoriasis (GPP)]] and [[Psoriasis classification#Classification|erythrodermic psoriasis]]. The [[pathophysiology]] consists of interactions between [[Cytokine|cytokines]], [[Dendritic cell|dendritic cells]] and [[T lymphocytes]] (particularly [[Th1]] and [[Th17]]). Psoriasis must be differentiated from other diseases that cause [[erythematous]], scaly [[Rash erythematous|rash]] such as [[Cutaneous T cell lymphoma]]/[[mycosis fungoides]], [[pityriasis rosea]], [[pityriasis rubra pilaris]], [[pityriasis lichenoides chronica]], [[nummular dermatitis]], [[secondary syphilis]], [[bowen’s disease]], [[exanthematous pustulosis]], [[Lichen planus|hypertrophic lichen planus]], Sneddon–Wilkinson disease, [[Parapsoriasis|small plaque parapsoriasis]], [[intertrigo]], [[langerhans cell histiocytosis]], [[dyshidrotic dermatitis]], [[tinea manuum]]/pedum/[[Tinea capitis|capitis]] and [[seborrheic dermatitis]]. The [[prevalence]] of psoriasis is estimated to be 500 per 100,000 cases to 4600 per 100,000 cases annually. The mainstay of therapy for psoriasis is [[topical]] agents applied directly onto the lesions. [[Topical]] agents include [[Corticosteroid|corticosteroids]], [[vitamin D]] analogues, [[tar]], [[anthralin]], [[tazarotene]], [[calcineurin]] inhibitors and [[aloe vera]] extracts. [[Systemic]] therapy may also be used which includes [[Immunosuppresive drug|immunosupressants]] to counter act the disease process. | ||
==Historical Perspective== | ==Historical Perspective== | ||
Revision as of 17:03, 28 July 2017
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Syed Hassan A. Kazmi BSc, MD [2]
Overview
Psoriasis is a systemic, immune-mediated disease, characterized by inflammation of the skin and joints. It commonly causes red scaly patches to appear on the skin. The scaly patches caused by psoriasis, called psoriatic plaques, are areas of inflammation and excessive skin production. Skin rapidly accumulates at these sites and takes a silvery-white appearance. Plaques frequently occur on the skin of the elbows and knees, but can affect any area including the scalp and genitals. Psoriasis is hypothesized to be immune-mediated and is not contagious.The disorder is a chronic recurring condition which varies in severity from minor localized patches to complete body coverage. Fingernails and toenails are frequently affected (psoriatic nail dystrophy). Psoriasis can also cause inflammation of the joints, which is known as psoriatic arthritis and 10-15% of people with psoriasis have psoriatic arthritis. The International Psoriasis Council, identifies four main forms of psoriasis which are plaque-type psoriasis, guttate psoriasis, generalized pustular psoriasis (GPP) and erythrodermic psoriasis. The pathophysiology consists of interactions between cytokines, dendritic cells and T lymphocytes (particularly Th1 and Th17). Psoriasis must be differentiated from other diseases that cause erythematous, scaly rash such as Cutaneous T cell lymphoma/mycosis fungoides, pityriasis rosea, pityriasis rubra pilaris, pityriasis lichenoides chronica, nummular dermatitis, secondary syphilis, bowen’s disease, exanthematous pustulosis, hypertrophic lichen planus, Sneddon–Wilkinson disease, small plaque parapsoriasis, intertrigo, langerhans cell histiocytosis, dyshidrotic dermatitis, tinea manuum/pedum/capitis and seborrheic dermatitis. The prevalence of psoriasis is estimated to be 500 per 100,000 cases to 4600 per 100,000 cases annually. The mainstay of therapy for psoriasis is topical agents applied directly onto the lesions. Topical agents include corticosteroids, vitamin D analogues, tar, anthralin, tazarotene, calcineurin inhibitors and aloe vera extracts. Systemic therapy may also be used which includes immunosupressants to counter act the disease process.
Historical Perspective
Psoriasis was first described during ancient times and named "Tzaraat" in the Bible, which also included other skin conditions. At first, psoriasis, leprosy and other inflammatory skin conditions were though to be the same but with the advancement of medical science, it became known to be a separate entity. The pathophysiology of psoriasis was described in 1960's and 1970's after histopathological study of the disease. The application of cat feces to red lesions on the skin, for example, was one of the earliest topical treatments employed in ancient Egypt. Onions, sea salt and urine, goose oil and semen, wasp droppings in sycamore milk, and soup made from vipers have all been reported as being ancient treatments. Sulfur was fashionable as a treatment for psoriasis in the Victorian and Edwardian eras and has gained importance again in the modern era as a substitute for other treatments. Psoriasis is a life-long disease with multiple relapses and remissions but symptoms can be controlled by medications.
Classification
Psoriasis can be classified according to clinical appearance, morphology and localization. The International Psoriasis Council, identifies four main forms of psoriasis which are plaque-type psoriasis, guttate psoriasis, generalized pustular psoriasis (GPP) and erythroderma. Several further subphenotypes have been named according to distribution (localized vs. widespread), anatomical localization (flexural- also called inverse, scalp, palms/soles/nail), size (large vs. small) and thickness (thick vs. thin) of plaques, onset (early vs. late), and disease activity (active vs. stable)
Pathophysiology
Psoriasis is an immune-mediated disease with genetic predisposition, but no specific immunogen has been identified. The pathophysiology consists of interactions between cytokines, dendritic cells and T lymphocytes(particularly Th1 and Th17).
Causes
Psoriasis is caused due to complex interactions between the genetics, immune system and environmental factors.
Differentiating Psoriasis from other Diseases
Psoriasis must be differentiated from other diseases that cause erythematous, scaly rash such as Cutaneous T cell lymphoma/mycosis fungoides, pityriasis rosea, pityriasis rubra pilaris, pityriasis lichenoides chronica, nummular dermatitis, secondary syphilis, bowen’s disease, exanthematous pustulosis, hypertrophic lichen planus, Sneddon–Wilkinson disease, small plaque parapsoriasis, intertrigo, langerhans cell histiocytosis, dyshidrotic dermatitis, tinea manuum/pedum/capitis and seborrheic dermatitis.
Epidemiology and Demographics
The prevalence of psoriasis is estimated to be 500 per 100,000 cases to 4600 per 100,000 cases annually. Psoriasis usually affects individuals of the Caucasian race. Psoriasis tends to affect Northern European and South East Asian countries.
Risk Factors
The most potent risk factor in the development of psoriasis is autoimmunity. Other risk factors include genetic predisposition and environmental factors.
Screening
There is no consensus for screening for psoriasis among the general population but there are screening tools, which can be used for screening for psoriasis, for example, the psoriasis screening tool (PST) and genetic testing.
Natural History, Complications and Prognosis
If left untreated, patients with psoriasis may progress to develop psoriatic arthritis, joint erosions and conjunctivitis. Common complications of psoriasis include depression, psoriatic arthritis, chronic inflammatory bowel disease, non-alcoholic fatty liver disease, celiac disease, sensorineural hearing loss, osteopenia and osteoarthritis. Psoriasis is a life-long disease with multiple relapses and remissions but symptoms can be controlled by medications.
Diagnosis
History and Symptoms
The hallmark of psoriasis is a papulosquamous, erythematous, scaly rash which can be commonly found on extensor surfaces of multiple body parts (although flexural surfaces may also be involved in inverse psoriasis). Patients with psoriasis usually give history of recent streptococcal throat infection, viral infection, immunization, use of antimalarial drugs, and trauma. The most common symptoms of psoriasis include pain, which has been described by patients as unpleasant, superficial, sensitive, itchy, hot or burning (especially in erythrodermic psoriasis and in some cases of traumatized plaques or in the joints affected by psoriatic arthritis). Patients also present with pruritus (especially in eruptive, guttate psoriasis), high fever in erythrodermic and pustular psoriasis. Other symptoms include dystrophic nails, long-term erythematous scaly rash with recent presentation of arthralgia/arthralgia without any visible skin findings, redness and tearing of eyes due to conjunctivitis or blepharitis and avoidance of situations requiring social interaction.
Physical Examination
On physical examination, psoriasis is characterized by erythematous, scaling papules and plaques.
Laboratory Findings
Laboratory findings consistent with the diagnosis of psoriasis include parakeratosis, vascular dilation, spongiform pustules of Kogoj and Munro's microabscesses on hemotoxylin and eosin staining of an affected area of skin. ELISA may show increased levels of Long Pentraxin 3 protein (PTX3). Complement levels may be increased.
X-Ray
There are no X ray findings associated with psoriasis. However it can be used to diagnose psoriatic arthritis which may lead to erosion of bone tissue and characeristic "pencil in cup" deformities. It may also lead to periostitis, dactylitis or arthritis mutilans.
CT scan
There are no CT scan findings associated with psoriasis.
MRI
There are no MRI findings associated with psoriasis
Other Diagnostic Findings
There are no other diagnostic findings associated with psoriasis.
Treatment
Medical Therapy
The mainstay of therapy for psoriasis is topical agents applied directly onto the lesions. Topical agents include corticosteroids, vitamin D analogues, tar, anthralin, tazarotene, calcineurin inhibitors and aloe vera extracts. Systemic therapy may also be used which includes immunosupressants to counter act the disease process.
Surgery
Tonsillectomy may be used as a treatment for psoriasis.
Primary Prevention
There is no primary prevention for psoriasis.
Secondary Prevention
Future or Investigational Therapies
Social Impact
The quality of life is an important factor in evaluating the severity of the disease. There are many treatments available but because of its chronic recurrent nature psoriasis is a challenge to treat.