Pseudogout (calcium pyrophosphate deposition): gout's crystal cousin
Last updated September 3, 2026.
Pseudogout (the calcium pyrophosphate deposition disease, CPPD) is the arthritis caused by the calcium-crystals depositing in the joints: producing the gout-like attacks (the sudden red-hot-swollen joint: the knee the classic, the wrist-and-others too), but driven by a different crystal, favoring the different joints, and treated through the flare-managing rather than the uric-acid-lowering. It favors the over-60s, the attacks settle over the days-to-weeks, and the long-term row is the flare-prevention and the joint-protecting rather than the crystal-removing (no CPPD-dissolving drug exists yet).
What does a flare feel like?
The sudden-kind attack: the joint hot-red-swollen-and-severely-painful (the knee the commonest, the wrist-shoulder-ankle next), the fever-and-feeling-ill possible (the mimicking-the-infection kind: the septic arthritis the crucial exclusion), the peaking within the day, the settling over the days-to-weeks. Between the flares: the normal or the chronically-stiff kind (the osteoarthritis-overlapping row: the wrists-knees the typical map).
Why does it happen?
The calcium-pyrophosphate crystals forming in the cartilage (the age the big driver: the over-60s row), the triggers for the attacks (the illness, the surgery, the injury, the dehydration: the stress-on-the-body rows), and the underlying-conditions row (the low-magnesium, the overactive-parathyroid, the hemochromatosis, the low-thyroid: the worth-checking kind in the under-60s). Mostly the nobody's-fault aging-kind row.
How is it treated?
- The flare treated: the joint-aspiration (the fluid drawn: the diagnosis confirmed under the microscope AND the pressure relieved), the steroid injection (the fast-settling kind), the NSAIDs-or-colchicine (the short-course kind: the kidney-and-stomach cautions in the older rows), and the rest-ice-elevation.
- The infection excluded first: the hot-swollen joint rule (the septic arthritis the cannot-miss: the fluid checked for the bugs as well as the crystals).
- The prevention-row: the low-dose colchicine for the frequent-flare kind, the underlying-conditions fixed (the magnesium, the parathyroid rows), and the no-dissolver honesty (the crystals stay: the flares managed).
- The chronic-kind joints managed: the strengthening-and-load management for the osteoarthritis-overlap rows.
When is it urgent?
The same-day for: the hot-red-swollen joint with the fever (the infection must be excluded fast), the joint too painful to bear weight, and the flare during the blood-thinner-or-kidney-disease rows (the treatment-planning kind). Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
What a Pymander AI doctor consult looks like
Illustrative example, not a real member's messages.
Common questions
So this is not gout? Why is it called pseudogout?
The name is the honest confession (the pseudo = the false: the mimicking-kind), and the two conditions differ: the gout deposits the uric-acid crystals (the big-toe classic: the diet-and-alcohol-linked kind), the pseudogout deposits the calcium-pyrophosphate (the knee-wrist-shoulder kind: the age-linked row), and the crucial practical fork: the gout's crystals can be dissolved by the drugs (the allopurinol-kind lowering the uric acid: the cure-the-cause row), while the CPPD crystals cannot (the no-dissolver row), so the pseudogout management is the flare-treating plus the flare-preventing, not the crystal-clearing.
Will the crystals ever go away?
The no-dissolver row, honestly: the calcium-pyrophosphate crystals, once deposited in the cartilage, stay (the no medication removes them yet: the research-row ongoing), so the flares can recur (the typically the few-times-a-year kind at worst), and the management targets the frequency-and-severity instead (the fast flare-treatment, the colchicine-prevention for the frequent kind, the trigger-management: the hydration, the illness-promptness). The many find the flares spacing out over the years, and the joint-protection rows (the strengthening, the weight-management) help the between-flare knee.
Why did they drain the fluid? Was that necessary?
The doubly-necessary row: the diagnosis (the fluid under the microscope shows the crystals: the rhomboid-kind confirming the CPPD, AND the culture excluding the infection: the septic arthritis is the cannot-miss row, especially with your fever), and the treatment (the pressure off the joint: the pain easing substantially as the fluid leaves, often with the steroid injected in the same procedure). The drainage is the single most useful intervention in the acute attack: uncomfortable for the minutes, relieving for the week.
Is there anything that triggers my attacks? Can I prevent them?
The recognized-trigger rows: the intercurrent illness, the surgery, the injury, and the dehydration (the body-stress kind: the crystal-shedding rows), so the prevention is the partial kind (the hydration matters, the prompt-illness-treatment, the protecting-the-knee row), plus the medication-kind for the frequent flares (the low-dose colchicine daily: the flare-frequency reduced in the trials: the ask-your-doctor row at your two-in-six-months rate), and the underlying-check row (the magnesium, the parathyroid, the thyroid, the iron: the bloods once: the fixable-kind contributors).
Is this damaging my knee permanently?
The mixed-kind honest row: the individual flares settle without the permanent harm mostly, but the CPPD associates with the joint-wear over the years (the chronic-kind row: the osteoarthritis-overlapping pattern: the wrists-knees map), so the joint-protection strategy matters (the quadriceps-strengthening: the protective kind, the weight-management, the sensible-load row), and the flare-frequency control is part of the protection (the fewer flares, the less cumulative inflammation). The physiotherapy referral is the worth-asking row for the long-term knee.
Could something else be causing this at 68?
The age-kind row is the expected one (the CPPD is the over-60s disease mostly: the cartilage chemistry changing with the age), but the standard-practice row checks the contributors once (the blood tests: the calcium-and-parathyroid, the magnesium, the thyroid, the iron: the hemochromatosis-kind: the fixable causes when found), and the family-kind rows exist (the rare inherited kinds: the earlier-onset clue). For the 68-year-old with the knee flares, the usual answer is the age-row: but the one-time bloods are the cheap, sensible completion.