Worsening Lateral Foot Pain And Swelling In A 26-year-old Female

HISTORY: A 26-year-old female presents with right lateral foot pain for the last three months. She rated it at 10/10 in severity and described it as a cramping, throbbing, and aching sensation. The pain initially responded to acetaminophen. She endorsed swelling. She reported stiffness with associated neck pain, especially in the morning. She denied any numbness, weakness, or tingling. Denied any trauma. PHYSICAL EXAMINATION: Examination revealed notable lateral swelling and tenderness to palpation over the 5th metatarsal base. Strength was 5/5 for resisted dorsiflexion, plantar flexion, inversion and eversion. Full range of motion of the ankle was performed with notable pain on inversion and resisted eversion. Negative anterior drawer test and negative talar test. Gait was slightly antalgic. DIFFERENTIAL DIAGNOSIS: 1. Peroneal tendinopathy Strain of cervical paraspinal muscles 2. Fifth metatarsal stress fracture 3. Lateral ankle sprain TEST AND RESULTS: Foot radiographs dorsoplantar, medial oblique and lateral projection— no osseous abnormalities.Non Contrast MRI of the right mid foot— T2 hyperintensity of the proximal half of the fifth metatarsal, proximal half of the fourth metatarsal and lateral aspect of the cuboid is present.— Tl signal alteration of the marrow space is present in the same regions more significant at the base of the fourth and fifth metatarsal with patchy TI signal alteration in the lateral cuboid. — Subtle areas of transverse low TI signal intensity are seen at the base of the fourth metatarsal. — Fourth and fifth MTP joint effusion is present.Foot radiographs— Erosive deformities without productive disease and joint narrowing in the right 4th and 5th tarsometatarsal joints. FINAL WORKING DIAGNOSIS: High grade stress injury of the 4th and 5th metatarsals and cuboid 2/2 erosive rheumatoid arthritis TREATMENT AND OUTCOMES: 1. Immobilization and stability provided with right CAM walking boot. 2. Referral to rheumatology made after minimal improvement with physical therapy and CAM boot. 3. Insurance was lost and was briefly lost to follow up. 4. Further workup revealed seropositive rheumatoid arthritis. 5. Symptomatic improvement with disease-modifying antirheumatic drugs.