Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatmentPrevention
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Diagnosis
Treatment
Prevention
Psoriatic arthritis(PsA) is a type ofinflammatory arthritisthat causes joint inflammation and pain throughout the body. It most commonly affects the fingers, toes, knees, ankles, and theentheses, the areas where tendons and ligaments meet bone.
PsA often causes a condition calledsacroiliitis, which is inflammation of thesacroiliac (SI) joints.Sacroiliitiscommonly causes pain in the hips, low back, buttocks, and legs. This article will discuss how these two conditions relate, including symptoms, causes, and treatment.
Verywell / Jessica Olah
Sacroiliitis is seen in 34%–78% of people who have psoriatic arthritis.It also affects up to 23% of people withpsoriasiswho do not have peripheral joint involvement.Psoriasisis an inflammatory skin condition that causes skin cell growth to speed up and build up as scales on the skin.
Psoriatic ArthritisMorning joint stiffnessEnthesitis (inflammation of the entheses)Dactylitis (finger and toe joint inflammation)FatigueSkin rashes or plaques (raised, dry, red patches)Nail symptoms—pitting, discoloration, nailbed separationChest and rib painEye inflammationSacroiliitisPain in the low back, buttocks, hips, thighs, and groinPain that extends into the legsPain that worsens after sitting or standing for long periodsPain when getting up from a sitting positionStiffness of hips and back, especially in the morning and after sitting for too longStiff spineLow-grade feverSpine fusingFractures (broken bones)
Psoriatic ArthritisMorning joint stiffnessEnthesitis (inflammation of the entheses)Dactylitis (finger and toe joint inflammation)FatigueSkin rashes or plaques (raised, dry, red patches)Nail symptoms—pitting, discoloration, nailbed separationChest and rib painEye inflammation
Morning joint stiffness
Enthesitis (inflammation of the entheses)
Dactylitis (finger and toe joint inflammation)
Fatigue
Skin rashes or plaques (raised, dry, red patches)
Nail symptoms—pitting, discoloration, nailbed separation
Chest and rib pain
Eye inflammation
SacroiliitisPain in the low back, buttocks, hips, thighs, and groinPain that extends into the legsPain that worsens after sitting or standing for long periodsPain when getting up from a sitting positionStiffness of hips and back, especially in the morning and after sitting for too longStiff spineLow-grade feverSpine fusingFractures (broken bones)
Pain in the low back, buttocks, hips, thighs, and groin
Pain that extends into the legs
Pain that worsens after sitting or standing for long periods
Pain when getting up from a sitting position
Stiffness of hips and back, especially in the morning and after sitting for too long
Stiff spine
Low-grade fever
Spine fusing
Fractures (broken bones)
Psoriatic Arthritis
PsA affects around 0.06%–0.25% of the American population.The prevalence of PsA is low in the general population, but it is very common in people who have psoriasis. According to the National Psoriasis Foundation, it affects about 30% of people with psoriasis.
The main symptom of PsA is pain, swelling, and stiffness in and around the joints. This is because it is an autoimmune disease in which the immune system malfunctions and attacks healthy parts of the body. PsA is also a type ofspondyloarthritis, a group of inflammatory conditions that affect the back, pelvis, neck, and some larger joints.
Additional symptoms of PsA include:
Inflammation of the SI joints is one of the earliest signs of PsA. According to a small study reported in 2020, nearly 38% of participants with PsA showed evidence of sacroiliitis on imaging tests, and most were not reporting symptoms of the condition.Treating inflammation can prevent future back and spine problems in people with PsA.
Sacroiliitis
People with sacroiliitis have inflammation in one or both SI joints. The condition is either asymmetric (affecting one side) or symmetric (affecting both sides).
The SI joints sit between your sacrum and iliac bones in the lower back, at the area where the spine and pelvis meet. Their job is to carry the weight of the upper body when you are standing or walking.
Doctors are unsure how many people are living with sacroiliitis. According to Cleveland Clinic, it may affect 10%–15% of people who report back pain.
Common symptoms of sacroiliitis are:
Left untreated, sacroiliitis can affect your mobility. Untreated pain can make it harder for you to perform daily tasks,can disrupt your sleep, and can affect your mental health.
Sacroiliitis linked to conditions like PsA andankylosing spondylitis(another type of spondyloarthritis) can worsen with time and potentially affect the bones of your spine (the vertebrae), causing them to stiffen and fuse.
Fusing means the vertebrae grow together due to the calcification of the ligaments and discs between the vertebrae. When this occurs, the spine becomes immobile, brittle, and vulnerable to fractures.
PsA is an autoimmune disease that occurs when the body’s immune system malfunctions and attacks healthy cells. The overactive response causes inflammation of the joints and other body areas and the overproduction of skin cells.
The most well-known genes linked to PsA are those of the human leukocyte antigen (HLA) complex.Theseantigenshelp the immune system recognize the difference between the body’s normal proteins and foreign invaders, like bacteria and viruses.
Some variations of HLA genes are linked to the different types of PsA and PsA disease severity and progression. There are also non-HLA genes linked to PsA that affect the signaling of the immune system.
PsA can run in families. It is estimated that 40% of people with the condition have at least one family member with PsA or psoriasis.This means that if you have a close family member with PsA (a parent or sibling), you might be at an increased risk for PsA and/or psoriasis.
Some people with psoriasis are also at an increased risk for PsA. These might include people who have severe psoriasis, those who experience nail symptoms, and those with inflammatory eye disease.
Environmental factors might play a role too. Injuries, infections, chronic stress, cigarette smoking, alcohol consumption, and exposure to certain medicines can trigger disease development, especially in people with a family history of PsA.
Inflammation of the SI joints is what causes sacroiliitis. It is often linked to different types of inflammatory conditions. Many types of arthritis can lead to inflammation of the SI joints, including:
Other causes of sacroiliitis include:
There is no specific test to diagnose PsA. Diagnosis is based on symptom history and a physical examination. You should let your doctor know about any family history of PsA or psoriasis.
Sacroiliitis can sometimes be harder to diagnose because low back pain has many causes. But much like PsA, diagnosis starts with a medical history and a physical exam.
Your healthcare provider will also examine the entheses to determine if there are sore and tender areas. Enthesitis classically affects the heel and the bottom of the foot, including areas around the knees, pelvis, spine, rib cage, shoulders, and elbows.
Skin examination for PsA looks for signs of psoriasis, including scaly red papules and plaques on the skin. Nail involvement in PsA might show nails that have ridges and nail bed separation.
Additional testing for PsA includes:
In addition, your healthcare provider might apply pressure to the SI joints, spine, hips, or legs. The more pain the applied pressure brings, the more likely a sacroiliitis diagnosis will be made.
Additional testing includes:
The main goal of treating PsA is to control the inflammation that affects the joints and skin. That will ease pain, improve symptoms, and prevent further damage. There are plenty of treatment options to help ease symptoms and protect your joints.
Treatment for sacroiliitis depends on the signs and symptoms experienced as well as the cause of those symptoms.
Medications are often helpful for managing PsA, and surgery might be an option if joint damage occurs. Your treatment options will depend on how severe your symptoms are. You may need to try more than one medication before finding one that works best to manage symptoms.
You can also add lifestyle changes and complementary and alternative medicine (CAM) therapies to your treatment plan.
Medicines used to treat PsA include:
Additional treatments for PsA are surgery, light therapy, lifestyle changes, and CAM therapies.
Sacroiliitis is managed with medications, physical therapy, lifestyle therapies, and different types of medical procedures.
Depending on the cause of symptoms, medicines used to treat sacroiliitis might include:
Aphysical therapistcan help you learn stretches and range of motion exercises to manage joint flexibility and stabilize muscles and joints.
Lifestyle and home remedies for managing sacroiliitis include modifying or avoiding activities that worsen pain to reduce inflammation in the SI joints. Proper posture also helps to improve symptoms. Alternate between ice and heat to help relieve SI pain.
Additional therapies for sacroiliitis include injectable corticosteroids, radiofrequency denervation to damage nerve tissue causing SI pain, and electrical stimulation to reduce pain.Joint fusionsurgery involves fusing affected bones to help relieve sacroiliitis symptoms.
PsA and sacroiliitis are not preventable conditions. Even though researchers know what some people have a higher risk for PsA (those with psoriasis or a family history of psoriatic disease), there is no treatment or tool to prevent a person from getting PsA.
Summary
Psoriatic arthritis is a type of inflammatory arthritis that causes joint pain and inflammation throughout the body. It might also cause a skin rash and other symptoms like eye inflammation. Psoriatic arthritis is one of several conditions that lead to sacroiliitis, or inflammation of the sacroiliac joints. Sacroiliitis causes pain and stiffness in the low back, hips, buttocks, and legs.
A Word From Verywell
People with PsA are at a higher risk for sacroiliitis. If you have PsA and start to experience pain in your lower back, hips, and buttocks, reach out to your doctor. An MRI can help your doctor see inflammation occurring in the SI joints and make a diagnosis.
If you are diagnosed with sacroiliitis, it is important to keep PsA inflammation under control and properly manage symptoms that affect your SI joints. Early and aggressive treatment can prevent complications and permanent joint damage.
16 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Krawczyk-Wasielewska A, Skorupska E, Samborski W.Sacroiliac joint pain as an important element of psoriatic arthritis diagnosis.Postepy Dermatol Alergol. 30(2):108-112. doi:10.5114/pdia.2013.34161Ogdie A, Weiss P.The epidemiology of psoriatic arthritis.Rheum Dis Clin North Am. 41(4):545-568. doi:10.1016/j.rdc.2015.07.001National Psoriasis Foundation.Psoriasis statistics.Alpay-Kanıtez N, Çelik S, Bes C.Polyarthritis and its differential diagnosis.Eur J Rheumatol. 6(4):167-173. doi:10.5152/eurjrheum.2019.19145Braga MV, de Olveira SC, Vasconcelos AHC, et al.Prevalence of sacroiliitis and acute and structural changes on MRI in patients with psoriatic arthritis.Sci Rep; 10, 11580. doi:10.1038/s41598-020-68456-7Cleveland Clinic.Sacroiliitis.FitzGerald O, Haroon M, Giles JT, Winchester R.Concepts of pathogenesis in psoriatic arthritis: genotype determines clinical phenotype.Arthritis Res Ther. 17(1):115. doi:10.1186/s13075-015-0640-3MedlinePlus.Psoriatic arthritis.Eder L, Haddad A, Rosen CF, et al.The incidence and risk factors for psoriatic arthritis in patients with psoriasis: a prospective cohort study.Arthritis Rheumatol. 68(4):915-23. doi:10.1002/art.39494Mease PJ.Measures of psoriatic arthritis: Tender and Swollen Joint Assessment, Psoriasis Area and Severity Index (PASI), Nail Psoriasis Severity Index (NAPSI), Modified Nail Psoriasis Severity Index (mNAPSI), Mander/Newcastle Enthesitis Index (MEI), Leeds Enthesit.Arthritis Care Res(Hoboken). 63 Suppl 11:S64-85. doi:10.1002/acr.20577Arthritis Foundation.Enthesitis and PsASlobodin G, Hussein H, Rosner I, Eshed I.Sacroiliitis - early diagnosis is key.J Inflamm Res. 2018;11:339-344. doi:10.2147/JIR.S149494Cleveland Clinic.Psoriatic arthritis.Day MS, Nam D, Goodman S, et al.Psoriatic arthritis.J Am Acad Orthop Surg. 20(1):28-37. doi:10.5435/JAAOS-20-01-028Nakamura M, Farahnik B, Bhutani T.Recent advances in phototherapy for psoriasis.F1000Research. 5:F1000 Faculty Rev-1684. doi:10.12688/f1000research.8846.1Ghasemi-rad M, Attaya H, Lesha E, et al.Ankylosing spondylitis: A state of the art factual backbone.World J Radiol. 7(9):236-52. doi:10.4329/wjr.v7.i9.236
16 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Krawczyk-Wasielewska A, Skorupska E, Samborski W.Sacroiliac joint pain as an important element of psoriatic arthritis diagnosis.Postepy Dermatol Alergol. 30(2):108-112. doi:10.5114/pdia.2013.34161Ogdie A, Weiss P.The epidemiology of psoriatic arthritis.Rheum Dis Clin North Am. 41(4):545-568. doi:10.1016/j.rdc.2015.07.001National Psoriasis Foundation.Psoriasis statistics.Alpay-Kanıtez N, Çelik S, Bes C.Polyarthritis and its differential diagnosis.Eur J Rheumatol. 6(4):167-173. doi:10.5152/eurjrheum.2019.19145Braga MV, de Olveira SC, Vasconcelos AHC, et al.Prevalence of sacroiliitis and acute and structural changes on MRI in patients with psoriatic arthritis.Sci Rep; 10, 11580. doi:10.1038/s41598-020-68456-7Cleveland Clinic.Sacroiliitis.FitzGerald O, Haroon M, Giles JT, Winchester R.Concepts of pathogenesis in psoriatic arthritis: genotype determines clinical phenotype.Arthritis Res Ther. 17(1):115. doi:10.1186/s13075-015-0640-3MedlinePlus.Psoriatic arthritis.Eder L, Haddad A, Rosen CF, et al.The incidence and risk factors for psoriatic arthritis in patients with psoriasis: a prospective cohort study.Arthritis Rheumatol. 68(4):915-23. doi:10.1002/art.39494Mease PJ.Measures of psoriatic arthritis: Tender and Swollen Joint Assessment, Psoriasis Area and Severity Index (PASI), Nail Psoriasis Severity Index (NAPSI), Modified Nail Psoriasis Severity Index (mNAPSI), Mander/Newcastle Enthesitis Index (MEI), Leeds Enthesit.Arthritis Care Res(Hoboken). 63 Suppl 11:S64-85. doi:10.1002/acr.20577Arthritis Foundation.Enthesitis and PsASlobodin G, Hussein H, Rosner I, Eshed I.Sacroiliitis - early diagnosis is key.J Inflamm Res. 2018;11:339-344. doi:10.2147/JIR.S149494Cleveland Clinic.Psoriatic arthritis.Day MS, Nam D, Goodman S, et al.Psoriatic arthritis.J Am Acad Orthop Surg. 20(1):28-37. doi:10.5435/JAAOS-20-01-028Nakamura M, Farahnik B, Bhutani T.Recent advances in phototherapy for psoriasis.F1000Research. 5:F1000 Faculty Rev-1684. doi:10.12688/f1000research.8846.1Ghasemi-rad M, Attaya H, Lesha E, et al.Ankylosing spondylitis: A state of the art factual backbone.World J Radiol. 7(9):236-52. doi:10.4329/wjr.v7.i9.236
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Krawczyk-Wasielewska A, Skorupska E, Samborski W.Sacroiliac joint pain as an important element of psoriatic arthritis diagnosis.Postepy Dermatol Alergol. 30(2):108-112. doi:10.5114/pdia.2013.34161Ogdie A, Weiss P.The epidemiology of psoriatic arthritis.Rheum Dis Clin North Am. 41(4):545-568. doi:10.1016/j.rdc.2015.07.001National Psoriasis Foundation.Psoriasis statistics.Alpay-Kanıtez N, Çelik S, Bes C.Polyarthritis and its differential diagnosis.Eur J Rheumatol. 6(4):167-173. doi:10.5152/eurjrheum.2019.19145Braga MV, de Olveira SC, Vasconcelos AHC, et al.Prevalence of sacroiliitis and acute and structural changes on MRI in patients with psoriatic arthritis.Sci Rep; 10, 11580. doi:10.1038/s41598-020-68456-7Cleveland Clinic.Sacroiliitis.FitzGerald O, Haroon M, Giles JT, Winchester R.Concepts of pathogenesis in psoriatic arthritis: genotype determines clinical phenotype.Arthritis Res Ther. 17(1):115. doi:10.1186/s13075-015-0640-3MedlinePlus.Psoriatic arthritis.Eder L, Haddad A, Rosen CF, et al.The incidence and risk factors for psoriatic arthritis in patients with psoriasis: a prospective cohort study.Arthritis Rheumatol. 68(4):915-23. doi:10.1002/art.39494Mease PJ.Measures of psoriatic arthritis: Tender and Swollen Joint Assessment, Psoriasis Area and Severity Index (PASI), Nail Psoriasis Severity Index (NAPSI), Modified Nail Psoriasis Severity Index (mNAPSI), Mander/Newcastle Enthesitis Index (MEI), Leeds Enthesit.Arthritis Care Res(Hoboken). 63 Suppl 11:S64-85. doi:10.1002/acr.20577Arthritis Foundation.Enthesitis and PsASlobodin G, Hussein H, Rosner I, Eshed I.Sacroiliitis - early diagnosis is key.J Inflamm Res. 2018;11:339-344. doi:10.2147/JIR.S149494Cleveland Clinic.Psoriatic arthritis.Day MS, Nam D, Goodman S, et al.Psoriatic arthritis.J Am Acad Orthop Surg. 20(1):28-37. doi:10.5435/JAAOS-20-01-028Nakamura M, Farahnik B, Bhutani T.Recent advances in phototherapy for psoriasis.F1000Research. 5:F1000 Faculty Rev-1684. doi:10.12688/f1000research.8846.1Ghasemi-rad M, Attaya H, Lesha E, et al.Ankylosing spondylitis: A state of the art factual backbone.World J Radiol. 7(9):236-52. doi:10.4329/wjr.v7.i9.236
Krawczyk-Wasielewska A, Skorupska E, Samborski W.Sacroiliac joint pain as an important element of psoriatic arthritis diagnosis.Postepy Dermatol Alergol. 30(2):108-112. doi:10.5114/pdia.2013.34161
Ogdie A, Weiss P.The epidemiology of psoriatic arthritis.Rheum Dis Clin North Am. 41(4):545-568. doi:10.1016/j.rdc.2015.07.001
National Psoriasis Foundation.Psoriasis statistics.
Alpay-Kanıtez N, Çelik S, Bes C.Polyarthritis and its differential diagnosis.Eur J Rheumatol. 6(4):167-173. doi:10.5152/eurjrheum.2019.19145
Braga MV, de Olveira SC, Vasconcelos AHC, et al.Prevalence of sacroiliitis and acute and structural changes on MRI in patients with psoriatic arthritis.Sci Rep; 10, 11580. doi:10.1038/s41598-020-68456-7
Cleveland Clinic.Sacroiliitis.
FitzGerald O, Haroon M, Giles JT, Winchester R.Concepts of pathogenesis in psoriatic arthritis: genotype determines clinical phenotype.Arthritis Res Ther. 17(1):115. doi:10.1186/s13075-015-0640-3
MedlinePlus.Psoriatic arthritis.
Eder L, Haddad A, Rosen CF, et al.The incidence and risk factors for psoriatic arthritis in patients with psoriasis: a prospective cohort study.Arthritis Rheumatol. 68(4):915-23. doi:10.1002/art.39494
Mease PJ.Measures of psoriatic arthritis: Tender and Swollen Joint Assessment, Psoriasis Area and Severity Index (PASI), Nail Psoriasis Severity Index (NAPSI), Modified Nail Psoriasis Severity Index (mNAPSI), Mander/Newcastle Enthesitis Index (MEI), Leeds Enthesit.Arthritis Care Res(Hoboken). 63 Suppl 11:S64-85. doi:10.1002/acr.20577
Arthritis Foundation.Enthesitis and PsA
Slobodin G, Hussein H, Rosner I, Eshed I.Sacroiliitis - early diagnosis is key.J Inflamm Res. 2018;11:339-344. doi:10.2147/JIR.S149494
Cleveland Clinic.Psoriatic arthritis.
Day MS, Nam D, Goodman S, et al.Psoriatic arthritis.J Am Acad Orthop Surg. 20(1):28-37. doi:10.5435/JAAOS-20-01-028
Nakamura M, Farahnik B, Bhutani T.Recent advances in phototherapy for psoriasis.F1000Research. 5:F1000 Faculty Rev-1684. doi:10.12688/f1000research.8846.1
Ghasemi-rad M, Attaya H, Lesha E, et al.Ankylosing spondylitis: A state of the art factual backbone.World J Radiol. 7(9):236-52. doi:10.4329/wjr.v7.i9.236
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