Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatmentFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Diagnosis
Treatment
Frequently Asked Questions
Pencil-in-cup is a rare type of deformity associated witharthritis mutilans(AM), a severe form ofpsoriatic arthritis(PsA). The term “pencil-in-cup” is used to describe what the affected bone looks like on an X-ray. The appearance is similar to that of a bone having worn away and now resembling a sharpened pencil that is facing a bone that also has worn away and is now in the shape of a cup.
This deformity results in erosion of joints and bones in the hands and feet as a result of severeinflammationrelated to PsA. A pencil-in-cup deformity can cause movement and joint function problems.
If imaging shows signs of a pencil-in-cup deformity, it is important you start treatment right away to prevent further damage, which can happen pretty quickly.
BelindaPretorius / Getty Images
Pencil-in-Cup Deformity Symptoms
A pencil-in-cup deformity results from osteolysis (progressive bone destruction) related to AM. Joint erosion and bone destruction from AM usually occur in the hands and feet.
Pencil-in-cup deformities lead to joint deformities and the inability to move affected joints.Because they typically form in the hands and feet, pencil-in-cup deformities can affect the way you walk and your ability to use your hands.
A pencil-in-cup deformity may involve the telescoping of affected fingers or toes.Telescoping means that the bones have dissolved so much that it appears that one part of a bone has slid into another part, like the sections of a telescope.
Pencil-in-cup, telescoping, or both can keep you from moving your affected digits or making a fist. They can also make it harder to do everyday activities, including self-care.
Arthritis mutilans—the cause of pencil-in-cup deformities—leads to severe joint pain and swelling of the hands and feet. It can also cause the bones of the hands and feet to fuse.
AM is also linked toskin lesions, which appear before damaging arthritis occurs.Some people with AM may havenail changes, including nail thickening, separation, and discoloration.
Psoriatic AMis the most severe and rare form of PsA. It affects only 5% of people with psoriatic arthritis.There are no prevalence studies on pencil-in-cup deformities, but available research shows this type of deformity is generally present in the feet in the first decade of having AM associated with PsA.
Experts believe the main cause of PsA is a combination of genetic and environmental factors.Genetic researchshows that people with PsA who have two specific genes—HLA-B27 and DQB1*02—have an increased risk of developing arthritis mutilans.
Similar changes to pencil-in-cup deformities can be seen in a type of inflammatory arthritis calledrheumatoid arthritis(RA). RA mainly affects the joints, usually multiple joints at once on both sides of the body.
Unfortunately, the research on arthritis mutilans in RA is limited and outdated. One 2008 report shows AM affects around 4.4% of people living with long-standing or untreated RA.
A 2013 article published in theJournal of Rheumatologyreports that AM has been linked to many other conditions, includingsystemic lupus erythematosus(lupus),systemic sclerosis(scleroderma), juvenile idiopathic arthritis (JIA), multicentric reticulohistiocytosis (MRH), andcutaneous T cell lymphoma(a cancer that starts in the white blood cells called T cells).
X-rayscan help your doctor to see what exactly is happening in your joints and whether the source of your joint damage is AM.Ultrasoundandmagnetic resonance imaging(MRI) can also confirm a diagnosis of pencil-in-cup deformity and look for the severity of any type of bone destruction.
Ultrasound scans can detect inflammation where there are no symptoms and where severe joint damage has not yet occurred.MRI scans can give your doctor a more detailed picture of small changes in bone structures and surrounding tissues.
According to a 2015 review of psoriatic AM, doctors usually look for bone and joint destruction as a diagnostic marker for AM.They will also look for telescoping and shortening of fingers and toes.
Few inflammatory joint conditions lead to pencil-in-cup deformity, and PsA is the most commonly associated with this type of damage. However, if your medical team rules out psoriatic arthritis, they will want to look for markers of rheumatoid arthritis and other inflammatory arthritis conditions linked to pencil-in-cup deformities.
Pencil-in-cup deformities are common in cases where PsA is either undiagnosed or misdiagnosed.However, a misdiagnosis of a pencil-in-cup deformity is uncommon because of distinct X-ray imaging.Additional symptoms seen in AM and PsA can also help your doctor make a diagnosis.
Arthritis mutilans is a progressive condition. So, the sooner you’re diagnosed, the better chance you have of avoiding future joint damage.
Early treatment is vital to prevent bone loss associated with AM. Bone tissue loss cannot be reversed, but treating AM can slow down any future destruction. Early treatment may also help to preserve the function of your fingers and toes.
The goals of treating pencil-in-cup deformities are to prevent further bone damage, provide pain relief, and maintain function in your hands and feet.Your treatment options might include medicines, physical therapy and occupational therapy, and surgery.
Medicines
Your doctor may prescribe several different medicines for treating pencil-in-cup deformities that have resulted from PsA. These may be given alone or together:
Physical and Occupational Therapy
Both physical and occupational therapy can help to relieve pain and other symptoms from pencil-in-cup deformities and keep the deformity from worsening. These therapies can also help to take the strain off your hands and feet, stop PsA from causing further damage, and keep your joints flexible and mobile.
Surgery
Surgery for pencil-in-cup deformities is usually a last resort. Surgical options your doctor might recommend to treat a pencil-in-cup deformity include joint fusion,joint replacement, or reconstructive surgery.
Summary
Pencil-in-cup deformity is a rare type of bone destruction seen in the fingers and toes of people with arthritis mutilans. This condition is usually associated with psoriatic arthritis. The change in bone shape can make it difficult to move the affected digits. Medications may be used to slow the destruction and relieve symptoms.
A Word From Verywell
A pencil-in-cup deformity cannot be reversed, but there are many treatment options to slow down or stop further damage. Psoriatic arthritis mutilans is not always preventable, but following your psoriatic arthritis treatment plan can keep inflammation under control and slow down the progression of PsA and psoriatic AM.
It is also possible to achieve remission from PsA with the many treatment options available for the condition. Remission means the condition is inactive, or a person is experiencing low disease activity.
Remission might reduce your risk for AM or joint damage from PsA. Even with remission, you will still need to stay on top of your treatment plan to keep the disease from worsening and the symptoms from returning.
How common is arthritis mutilans?
Arthritis mutilans is a severe, rare, and extremely destructive type of arthritis. It affects about 5% of people with severe psoriatic arthritis. It is also seen with some other types of inflammatory arthritis, but it is even rarer in other conditions.
What does pencil-in-cup mean on an X-ray?
Is pencil-in-cup deformity permanent?
Pencil-in-cup deformities are the result of arthritis mutilans. AM can cause bone loss, which leads to changes in the shape of your fingers and toes and impairs your movement. AM leads to permanent damage to your fingers, toes, hands, and feet. Pencil-in-cup deformities are also permanent, and if left to worsen, they will later require surgery to repair the damage.
12 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.Chandran V, Gladman DD, Helliwell PS, Gudbjörnsson B.Arthritis mutilans: a report from the GRAPPA 2012 annual meeting.J Rheumatol.2013 Aug;40(8):1419-22. doi:10.3899/jrheum.130453Laasonen L, Gudbjornsson B, Ejstrup L, et al.Radiographic development during three decades in a patient with psoriatic arthritis mutilans.Acta Radiol Open. 2015;4(7):2058460115588098. doi:10.1177/2058460115588098Mochizuki T, Ikari K, Okazaki K.Delayed diagnosis of psoriatic arthritis mutilans due to arthritis prior to skin lesion.Case Rep Rheumatol. 2018;2018:4216938. doi:10.1155/2018/4216938Bell L, Murphy CL, Wynne B, Cunnane G.Acute presentation of arthritis mutilans.J Rheumatol. 2011;38(1):174-5. doi:10.3899/jrheum.100579Lloyd P, Ryan C, Menter A.Psoriatic arthritis: An update.Arthritis. 2012;2012:176298. doi:10.1155/2012/176298Aliu O, Netscher DT, Peltier M.Failure of small joint arthrodesis from resorption around a compression screw in a patient with lupus-associated arthritis mutilans: case report.Hand(N Y). 2008;3(1):72-75. doi:10.1007/s11552-007-9055-1 Note to copy editor: this is sufficiently pointed out as being older, but should keep.Butendieck RR Jr, Abril A.Idiopathic arthritis mutilans.J Rheumatol. 2013 Nov;40(11):1921-2. doi:10.3899/jrheum.130236Kaeley GS, Bakewell C, Deodhar A.The importance of ultrasound in identifying and differentiating patients with early inflammatory arthritis: a narrative review.Arthritis Res Ther.2020;22,1. doi:10.1186/s13075-019-2050-4Haddad A, Johnson SR, Somaily M, et al.Psoriatic arthritis mutilans: Clinical and radiographic criteria. A systematic review.J Rheumatol. 2015 Aug;42(8):1432-8. doi:10.3899/jrheum.141545Mease PJ, Armstrong AW.Managing patients with psoriatic disease: the diagnosis and pharmacologic treatment of psoriatic arthritis in patients with psoriasis.Drugs. 2014;74(4):423-441. doi:10.1007/s40265-014-0191-yCuchacovich R, Perez-Alamino R, Garcia-Valladares I, Espinoza LR.Steps in the management of psoriatic arthritis: A guide for clinicians.Ther Adv Chronic Dis. 2012;3(6):259-269. doi:10.1177/2040622312459673Krakowski P, Gerkowicz A, Pietrzak A, et al.Psoriatic arthritis - new perspectives.Arch Med Sci.2019;15(3):580-589. doi:10.5114/aoms.2018.77725
12 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.Chandran V, Gladman DD, Helliwell PS, Gudbjörnsson B.Arthritis mutilans: a report from the GRAPPA 2012 annual meeting.J Rheumatol.2013 Aug;40(8):1419-22. doi:10.3899/jrheum.130453Laasonen L, Gudbjornsson B, Ejstrup L, et al.Radiographic development during three decades in a patient with psoriatic arthritis mutilans.Acta Radiol Open. 2015;4(7):2058460115588098. doi:10.1177/2058460115588098Mochizuki T, Ikari K, Okazaki K.Delayed diagnosis of psoriatic arthritis mutilans due to arthritis prior to skin lesion.Case Rep Rheumatol. 2018;2018:4216938. doi:10.1155/2018/4216938Bell L, Murphy CL, Wynne B, Cunnane G.Acute presentation of arthritis mutilans.J Rheumatol. 2011;38(1):174-5. doi:10.3899/jrheum.100579Lloyd P, Ryan C, Menter A.Psoriatic arthritis: An update.Arthritis. 2012;2012:176298. doi:10.1155/2012/176298Aliu O, Netscher DT, Peltier M.Failure of small joint arthrodesis from resorption around a compression screw in a patient with lupus-associated arthritis mutilans: case report.Hand(N Y). 2008;3(1):72-75. doi:10.1007/s11552-007-9055-1 Note to copy editor: this is sufficiently pointed out as being older, but should keep.Butendieck RR Jr, Abril A.Idiopathic arthritis mutilans.J Rheumatol. 2013 Nov;40(11):1921-2. doi:10.3899/jrheum.130236Kaeley GS, Bakewell C, Deodhar A.The importance of ultrasound in identifying and differentiating patients with early inflammatory arthritis: a narrative review.Arthritis Res Ther.2020;22,1. doi:10.1186/s13075-019-2050-4Haddad A, Johnson SR, Somaily M, et al.Psoriatic arthritis mutilans: Clinical and radiographic criteria. A systematic review.J Rheumatol. 2015 Aug;42(8):1432-8. doi:10.3899/jrheum.141545Mease PJ, Armstrong AW.Managing patients with psoriatic disease: the diagnosis and pharmacologic treatment of psoriatic arthritis in patients with psoriasis.Drugs. 2014;74(4):423-441. doi:10.1007/s40265-014-0191-yCuchacovich R, Perez-Alamino R, Garcia-Valladares I, Espinoza LR.Steps in the management of psoriatic arthritis: A guide for clinicians.Ther Adv Chronic Dis. 2012;3(6):259-269. doi:10.1177/2040622312459673Krakowski P, Gerkowicz A, Pietrzak A, et al.Psoriatic arthritis - new perspectives.Arch Med Sci.2019;15(3):580-589. doi:10.5114/aoms.2018.77725
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.
Chandran V, Gladman DD, Helliwell PS, Gudbjörnsson B.Arthritis mutilans: a report from the GRAPPA 2012 annual meeting.J Rheumatol.2013 Aug;40(8):1419-22. doi:10.3899/jrheum.130453Laasonen L, Gudbjornsson B, Ejstrup L, et al.Radiographic development during three decades in a patient with psoriatic arthritis mutilans.Acta Radiol Open. 2015;4(7):2058460115588098. doi:10.1177/2058460115588098Mochizuki T, Ikari K, Okazaki K.Delayed diagnosis of psoriatic arthritis mutilans due to arthritis prior to skin lesion.Case Rep Rheumatol. 2018;2018:4216938. doi:10.1155/2018/4216938Bell L, Murphy CL, Wynne B, Cunnane G.Acute presentation of arthritis mutilans.J Rheumatol. 2011;38(1):174-5. doi:10.3899/jrheum.100579Lloyd P, Ryan C, Menter A.Psoriatic arthritis: An update.Arthritis. 2012;2012:176298. doi:10.1155/2012/176298Aliu O, Netscher DT, Peltier M.Failure of small joint arthrodesis from resorption around a compression screw in a patient with lupus-associated arthritis mutilans: case report.Hand(N Y). 2008;3(1):72-75. doi:10.1007/s11552-007-9055-1 Note to copy editor: this is sufficiently pointed out as being older, but should keep.Butendieck RR Jr, Abril A.Idiopathic arthritis mutilans.J Rheumatol. 2013 Nov;40(11):1921-2. doi:10.3899/jrheum.130236Kaeley GS, Bakewell C, Deodhar A.The importance of ultrasound in identifying and differentiating patients with early inflammatory arthritis: a narrative review.Arthritis Res Ther.2020;22,1. doi:10.1186/s13075-019-2050-4Haddad A, Johnson SR, Somaily M, et al.Psoriatic arthritis mutilans: Clinical and radiographic criteria. A systematic review.J Rheumatol. 2015 Aug;42(8):1432-8. doi:10.3899/jrheum.141545Mease PJ, Armstrong AW.Managing patients with psoriatic disease: the diagnosis and pharmacologic treatment of psoriatic arthritis in patients with psoriasis.Drugs. 2014;74(4):423-441. doi:10.1007/s40265-014-0191-yCuchacovich R, Perez-Alamino R, Garcia-Valladares I, Espinoza LR.Steps in the management of psoriatic arthritis: A guide for clinicians.Ther Adv Chronic Dis. 2012;3(6):259-269. doi:10.1177/2040622312459673Krakowski P, Gerkowicz A, Pietrzak A, et al.Psoriatic arthritis - new perspectives.Arch Med Sci.2019;15(3):580-589. doi:10.5114/aoms.2018.77725
Chandran V, Gladman DD, Helliwell PS, Gudbjörnsson B.Arthritis mutilans: a report from the GRAPPA 2012 annual meeting.J Rheumatol.2013 Aug;40(8):1419-22. doi:10.3899/jrheum.130453
Laasonen L, Gudbjornsson B, Ejstrup L, et al.Radiographic development during three decades in a patient with psoriatic arthritis mutilans.Acta Radiol Open. 2015;4(7):2058460115588098. doi:10.1177/2058460115588098
Mochizuki T, Ikari K, Okazaki K.Delayed diagnosis of psoriatic arthritis mutilans due to arthritis prior to skin lesion.Case Rep Rheumatol. 2018;2018:4216938. doi:10.1155/2018/4216938
Bell L, Murphy CL, Wynne B, Cunnane G.Acute presentation of arthritis mutilans.J Rheumatol. 2011;38(1):174-5. doi:10.3899/jrheum.100579
Lloyd P, Ryan C, Menter A.Psoriatic arthritis: An update.Arthritis. 2012;2012:176298. doi:10.1155/2012/176298
Aliu O, Netscher DT, Peltier M.Failure of small joint arthrodesis from resorption around a compression screw in a patient with lupus-associated arthritis mutilans: case report.Hand(N Y). 2008;3(1):72-75. doi:10.1007/s11552-007-9055-1 Note to copy editor: this is sufficiently pointed out as being older, but should keep.
Butendieck RR Jr, Abril A.Idiopathic arthritis mutilans.J Rheumatol. 2013 Nov;40(11):1921-2. doi:10.3899/jrheum.130236
Kaeley GS, Bakewell C, Deodhar A.The importance of ultrasound in identifying and differentiating patients with early inflammatory arthritis: a narrative review.Arthritis Res Ther.2020;22,1. doi:10.1186/s13075-019-2050-4
Haddad A, Johnson SR, Somaily M, et al.Psoriatic arthritis mutilans: Clinical and radiographic criteria. A systematic review.J Rheumatol. 2015 Aug;42(8):1432-8. doi:10.3899/jrheum.141545
Mease PJ, Armstrong AW.Managing patients with psoriatic disease: the diagnosis and pharmacologic treatment of psoriatic arthritis in patients with psoriasis.Drugs. 2014;74(4):423-441. doi:10.1007/s40265-014-0191-y
Cuchacovich R, Perez-Alamino R, Garcia-Valladares I, Espinoza LR.Steps in the management of psoriatic arthritis: A guide for clinicians.Ther Adv Chronic Dis. 2012;3(6):259-269. doi:10.1177/2040622312459673
Krakowski P, Gerkowicz A, Pietrzak A, et al.Psoriatic arthritis - new perspectives.Arch Med Sci.2019;15(3):580-589. doi:10.5114/aoms.2018.77725
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