htmn1,
Rapid onset joint pain, which is of this severity, is very concerning. The examining physician will want to know a bit about the patients history, including: allergies, medicines used, current and past illnesses, travel history, occupation, pets or animal contacts, vaccination history, sexual activity history, use of illicit substances, and possibly more.
Though septic arthritis (infected joint) is much more common in infants and children, it does occur in adults also. This is always near the top of the list in excruciatingly pain, rapid onset joint pain. It usually only affects one joint, but, it can be in multiple joints. Septic arthritis in adults is usually more common in IV drug abusers, sexually active individuals, and immunocompromised patients, but just ordinary people can get it also.
Septic arthritis is always ruled out early, because missing it or a significant delay in treating it can lead to destruction of the joint, systemic problems, and possibly even death. It is a significant condition in adults.
It could be an acute onset of one of the hundreds of inflammatory arthropathies. Often it initial presentation can be dramatic, then once under control, they usually quite down, with only periodic flares. These more commonly affect multiple joints.
There are many of these conditions, but Gout, Lyme Disease, Reiter's syndrome, inflammatory arthritis brought on by an allergic reaction, psoriatic arthritis, rheumatoid arthritis, SLE (Lupus) are just some of them.
An acute prolapse of a disc in the spine can cause referred pain to the dermatome of the nerve root(s) involved. Thus it could cause pain in the lower extremity, including the joints.
Sickle cell disease is another cause of acute onset joint pain. This is more common in certain ethnic groups.
There are certain tumors that can cause significant joint pain. PVN (pigmented villonodulus synovitis) is a common one, but usually it affects the knee, hip is less common.
As you can see, rapid or acute onset joint pain of an excurciating nature is very concerning for some serious conditions. In the absence of trauma, these condition have to be considered and ruled out.
A thorough examination of the whole body, looking for skin rashes or lesions, is important. Examination for infections in the throat or genitalia also should be done. Of course blood work must be done: CBC with differential, Chem 20, UA, ESR, CRP, RF, ANA, HIV, Hepatitis, Strep, Lyme titer, Uric acid level, and/or anything else that the examination directs.
If the pain your daughter has not decreased, or is increasing, she should be seen immediately. If she has a documented fever with a thermometer, that increases the need to be seen.
Hope your daughter is feeling better soon. Good luck.