joint problems

Question

My 13 year old daughter has CF and since 3 years now can’t stretch her fingers. Her joints are swollen and she has difficulty stretching her arms. Apart from not being able to stretch the fingers they function well.
She has been free of severe lung infection for the last few years, but takes amoxicillin as maintenance antibiotic.
Can these joint problems be related to CF ?

Answer

Your question seems very specific for your daughter and should surely be discussed with her CF physician. We can only give you general information on CF and joint problems.
The most common or typical joint problem in CF is called ‘CF – related arthropathy’. It’s only present in a minority of patients (2-8%), usually adolescents or adults. Signs and symptoms are pain and swelling of one or more joints, usually knee’s or ankles. The pain can last for days to weeks and improves with anti-inflammatory medicines. Joint destruction is rare and thus radiography does not show bone abnormalities. There is no clear correlation between this type of arthropathy and severity of lung disease in the CF patient.
Some antibiotics can lead to painfull joints. For example quinolones, used for the treatment of Pseudomonas aeruginosa, can cause tendinitis, merely of the Achilles tendon. It is less likely that ‘amoxycillin’ is responsible for joint problems. This antibiotic only rarely causes acute pain and joint swelling, which is then commonly associated with fever and rash.
It is known that CF patients have an increased risk for osteoporosis, meaning ‘less strong and thus more fragile bone’. Rachitis, due to vitamin D deficiency, should not occur if malabsorbtion is treated and vitamins are supplemented.
‘Hypertrophic osteoarthropathy’ is another type of bone and joint disease that can occur however mainly in adult CF patient with severe lung disease. It is characterized by painful swelling of one or more large joints like the knee, ankle, elbow or wrist with possible bone aches in the arms and the legs. Joints are swollen, red and less mobile. Apart from chronic joints pain, acute exacerbations can occur lasting days to weeks. With time the pain usually get worse. Radiography shows typical bone lesions. Intensive treatment of lung infection with antibiotics brings relief. Since chronic lung infection is nowadays treated much more intensively compared to years ago, the hypertrophic arthropathy is seen more rarely.
Classical rheumatoic arthritis can occur independent of CF, the incidence being maybe slightly higher in CF compared to the general population. In this disease, small and large joints can be involved. Most typical signs are painful red swelling of the joints, with morning stiffness.
Lastly, there are old reports in CF patient of shortened 4th (or 5th) handbone. This is however not associated with pain or decreased function.

To conclude: In a child with CF and mild to moderate lung disease, contraction and limited mobility of the fingers and elbows without pain are not suggestive for CF related bone or joint disease. You therefore should discuss this with your CF physician. He/she will carefully examine your child and decide if referral to a pediatric rheumatologist is indicated.
F. Vermeulen, M. Proesmans, K. De Boeck

04.12.2008