Pseudoparalysis of Parrot

If you have ever talked with a pediatric emergency medicine physician about some basic tenets of their practice, one of them will inevitably be, “Never trust a neonate.”  The first few months of life outside the womb can elucidate a myriad of problems that were previously hidden during the prenatal state.  We have previously touched on congenital issues like Congenital Adrenal Hyperplasia, Congenital Pulmonary Airway Malformation, Neonatal Leukemia, and of course there is always the Inconsolable Infant. Unfortunately, the possibility of congenital infections always looms large as well, including congenital syphilis.  We have touched on the treatment for older children with syphilis with Bicillin CR vs LA. We have discussed how syphilis may cause Uveitis in older children.  Now, let’s discuss another complication of “The Great Mimicker” which may throw us for a loop in the ED – Pseudoparalysis of Parrot:

Pseudoparalysis of Parrot – Basics

  • First described by Jules Marie Parrot in 1871. [Kocher 1996, Pereira 2017]
  • It is a complication of congenital syphilis, causing local periostitis, intense pain, and subsequent decreased movement. [Kocher 1996, Pereira 2017]
  • Syphilis is on the rise in the US. In 2021 there were almost 177,000 cases of syphilis. [CDC 2023]
  • In 2021, there were over 2800 cases of congenital syphilis, tripled from 2017.  [CDC 2023]

Pseudoparalysis of Parrot – Presentation and Exam

  • Infant presents with lack of movement of one or both upper extremities, and will cry with palpation. [Kocher 1996, Pereira 2017, Li 2021]
  • Typically affects the upper limbs, usually is bilateral, and is polyostotic (involves multiple bones)  [Kocher 1996, Pereira 2017]
  • Causes a periostitis of the metaphysis of the bones, and can cause metaphyseal erosions from spirochetes in the bones [Kocher 1996, Pereira 2017]
  • This link contains great pictures and a video to demonstrate the presentation from this case report: https://www.jpeds.com/article/S0022-3476(17)31051-X/fulltext  [Pereira 2017]
  • Infants with congenital syphilis may also have other clinical findings:
    • rhinorrhea (“the snuffles”),
    • hepato- or splenomegaly,
    • a rash,
    • or abnormal labs.
    • However, the musculoskeletal complaints may be the first presenting symptom!

Pseudoparalysis of Parrot – Diagnosis

  • Radiographically evident periostitis in up to 95% of symptomatic patients  [Kocher 1996, Pereira 2017]
  • Radiographs can show bone reaction and bone destruction, manifesting as “transverse, saw-tooth, dense bands from altered mineralization at the zone of provisional calcification”  [Kocher 1996]
  • Wimberger sign is specifically focal erosion of bone at the medial proximal tibial metaphysis.  [Kocher 1996]
  • Must consider alternative diagnoses as well, including [Kocher 1996]
  • Screen for congenital syphilis with non-treponemal antibody testing with an RPR (rapid plasma reagin) or VDRL (venereal disease research laboratory). 
  • Confirm a positive result with either a Fluorescent treponemal antibody absorption (FTA-ABS) and/or micro hemagglutination test for antibodies to T.Pallidum (MHA-TP). [Hussain 2023]

Pseudoparalysis of Parrot – Treatment [CDC 2021]

  • Up to 4 weeks of age [CDC 2021]
    • Aqueous Crystalline Penicillin G – 50,000 units/kg per dose IV every 12 hours for first 7 days. THEN- 50,000 units/kg per dose IV every 8 hours for 10 to 14 days.
    • Alternative: Procaine penicillin G, 50,000 units/kg/day IM for 10 to 14 days.
  • Greater than 4 weeks of age
    • Aqueous Penicillin G – 50,000 units/kg per dose every 6 hours intravenously for 10 to 14 days.
  • If there is a penicillin allergy, the child should be desensitized and then treated with penicillin to ensure appropriate treatment.
  • If a non-penicillin agent is used, close serum and CSF monitoring needed, along with discussion with an expert (like an infectious disease specialist)
  • If IV Penicillin G is not available due to shortage, Procaine Penicillin G IM (50,000 Units/kg/dose to max of 2.4 million units/day) for 10 days should be used instead
  • If IM Procaine Penicillin G is not available, can use Ceftriaxone, but must consult an expert (like infectious disease specialist) and follow closely because there is poor evidence to support Ceftriaxone as a reliable treatment for syphilis.
    • For infants older than 30 days – ceftriaxone 75 mg/kg/day IV or IM, single daily dose for 10–14 days
    • For children – ceftriaxone 100 mg/kg/day IV or IM, single daily dose for 10-14 days.
  • If a day of treatment is missed, the clock resets and the treatment duration must be started all over again.

Pseudoparalysis of Parrot –  Complications

  • May be misdiagnosed at first as birth trauma or a neurologic disorder. [Pereira 2017]
  • If pathologic fractures occur, may be misdiagnosed as non-accidental trauma. [Li 2021]
  • Delay in treatment or inadequate treatment of congenital syphilis can cause [Hussain 2023]
    • Intellectual Disability
    • Skin Gummas
    • Scarring
    • Hearing Deficits
    • Skeletal Abnormalities
  • Congenital syphilis can present with pathologic fractures as well.
  • The initiation of antibiotic therapy in some infants can lead to a Jarisch–Herxheimer reaction (fevers, chills, hypotension, and possibly fetal death) due to the intense inflammatory reaction of the body to dying spirochetes.  [Hussain 2023]
  • With proper treatment, bone lesions and periostitis resolve within 6 weeks or so and full recovery can be made. [Riani-Llano 1997]

Moral of the Morsel

  • Apparent paralysis isn’t always a nerve/cord problem! Stay vigilant and consider other causes for a baby to not move an extremity.
  • Ask about exposures! A thorough birth history is crucial.  If a mother had no or very little prenatal care, or multiple partners during pregnancy, consider congenital syphilis and other TORCH infections as a cause for infant illness.
  • A picture is worth 1,000 words!  Radiographic imaging of abnormal extremities can be very helpful in diagnosis.  Don’t skimp on the Xrays due to patient’s age.
References
  1. KOCHER, MININDER, CANIZA, MIGUELA, DURHAM, NORTH. Parrot Pseudoparalysis of the Upper Extremities. A Case Report*. J Bone Joint Surg Am. 1996;78(2):284-7. Cited in: Journals@Ovid Full Text at http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=reference&D=ovftb&NEWS=N&AN=00004623-199602000-00018. Accessed January 19, 2024.
  2. Pereira AA, Castro SM, Venturini RR, César FO, Fortes PM, Costa PS. Pseudoparalysis of Parrot: A diagnostic aid in congenital syphilis. The Journal of Pediatrics. 2017;190:282-282. doi:10.1016/j.jpeds.2017.07.048
  3. Sexually transmitted disease surveillance, 2021. Centers for Disease Control and Prevention. April 11, 2023. Accessed January 16, 2024.  https://www.cdc.gov/std/statistics/2021/default.htm.
  4. Yi Li, Scott V. Connelly, Pseudoparalysis of parrot – Re-emergence of the great mimicker, The American Journal of Emergency Medicine, Volume 48, 2021, Pages 378.e1-378.e2, ISSN 0735-6757, https://doi.org/10.1016/j.ajem.2021.04.038.
  5. Hussain SA, Vaidya R. Congenital Syphilis. [Updated 2023 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537087/
  6. Congenital syphilis – STI treatment guidelines. Centers for Disease Control and Prevention. July 22, 2021. Accessed January 19, 2024. https://www.cdc.gov/std/treatment-guidelines/congenital-syphilis.htm.
  7. Riani-Llano N. Index of Suspicion. Case 2. Pseudoparalysis of Parrot caused by congenital syphilis. Pediatr Rev. 1997;18(2):63-65.

Christyn Magill
Christyn Magill
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