A 6-month-old infant with swollen ankle (page1/3)
Prepared by.... Pia S. Pannaraj, MD.
Thanyawee Puthanakit, MD.
Patient: A 6-month-old infant presented with a red, swollen right ankle. Address: Chiang Mai

CC: Swollen Rt. ankle

Present Illness:
  8 days PTA, he suffered an unknown insect bite on the lateral maleolus. On the
following day, his mother noticed a red bump in this area; thus he was taken to a nearby clinic. He was diagnosed with cellulitis and prescribed dicloxacillin 67.5mg PO QID which he took with good compliance.
3 days PTA, he had increase swelling and redness of right ankle. He also developed a low-grade fever, increased fussiness and decreased appetite
Birth History: Born full term to G3P3 mother, normal labor, BW 3200 g, no complications
Past Medical History:
No previous hospitalizations or surgeries. No history of recurrent infections.
Immunizations: BCG, HVB, DTP, and OPV according to immunization schedule
Development: rolls over, sits with support
Social History: lives with mother, father, grandfather, and 2-year-old sibling
Physical examination:
  VS:: BT 37.7 C, HR 172/min, RR 46/min, BP 110/66 mmHg, weight 9.1 kg
General appearance: alert, active, crying
HEENT: nasal discharge, mildly injected pharynx, TMs normal
Neck: small cervical lymphadenopathy
Cardiovascular: regular rate and rhythm, normal S1, S2, no murmurs
Pulmonary: clear bilaterally
Abdomen: normal active bowel sounds, soft, nontender, no hepatosplenomegaly
Extremities: At the Rt foot: there is a 5 x 5 cm swollen area over lateral maleolus with erythema, edema, warmth, and tenderness to palpation. There is a small punctate lesion in center. The swollen area is fluctuated, but there is no crepitation.
The edema extends up to the knee, but there is no tenderness to palpation above ankle. There is decrease range of motion of Rt ankle and the dorsalis pedis pulse is difficult to palpate (secondary to edema).
Neuro exam: normal
Initial Laboratoy Tests:
 

> CBC: Hb 9.0g/dL, Hct 28.7%, WBC 30,000/mm3 (59% segmental neutrophils, 11% bands, 20% lymphocytes), Plt 986,000/mm3
> ESR: 50 mm/hr
> Electrolyte: Na 135 mmol/L, K 5.8 mmol/L, Cl 100 mmol/L, HCO3 22 mEq/L,
> BUN 8 g/dL, Cr 0.4 g/dL
> Rt ankle X-ray: soft tissue swelling no evidence of bone involvement.

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