Management of acute “flare-up” of

fibrodysplasia ossificans progressiva

with short-term use of high-dose

corticosteroids

Jung Yun Bae *, Tae-Joon Cho

Seoul National University Children’s Hospital *Pusan National University Yangsan Hospital

Fibrodysplasia Ossificans

Progressiva (FOP)

• A rare and disabling genetic condition characterized by congenital malformations of the great toes and progressive heterotopic endochondral ossification (HEO).

• A recurrent mutation in activin receptor IA/activin-like kinase-2 (ACVR1/ALK2), a bone morphogenetic protein (BMP) type I receptor, exists in all sporadic and familial cases of classic FOP.

• Mostly a spontaneous new mutation or autosomal dominant transmission.

Clinical features define classic FOP

• Malformations of the great toes and progressive heterotopic

endochondral ossification (HEO).

• Neck stiffness, spine anomaly.

• Hearing loss, sparse/thin scalp hair, mild cognitive impairment,

severe growth retardation, cataracts, retinal detachment…

• Flare-ups

Flare-ups ?

• During the first decade of life, most children with FOP develop

episodic, painful inflammatory soft tissue swellings

->”Flare-ups”.

• Flare-ups are episodic; immobility is cumulative.

• Aponeuroses, fascia, ligaments, tendons, and skeletal muscles

transform into mature heterotopic bone.

• Several skeletal muscles including the diaphragm, tongue, and

extra-ocular muscles are spared. Cardiac muscle and smooth

muscle are spared.

Triggers of Flare-ups

• Intramuscular injection.

• Mandibular blocks for dental work.

• muscle fatigue.

• blunt muscle trauma.

• Falls.

• influenza-like illnesses.

Radiologic findings

Radiologic findings

Treatment of FOP

• No definite treatment.

• Medical intervention is supportive.

• Surgical intervention is unsuccessful and risks new, trauma-

induced HO.

Purpose

• To analize the result of short-term use of high-dose cortico

steroids for management of acute “flare-up” of FOP.

Materials & Methods

• 7 cases

• Duration: 1997~2013

• F : M = 5 : 2

• Follow-up: Avg. 5 years (range, 0.25 - 16)

• Retrospective review of medical records and radiographs.

• Resimen: Prednisone – 2 mgs/kg once daily for four days

Patients Data Patient Gender Age Site Sx. Trauma Sx. onset

1 M 9 shoulder pain - 3DA

2 F 23 hip pain - 10 DA

3 M 16 Shoulder& neck pain

- 1DA

4 F 8 Submandibular area pain & stiffness + 5DA

5 F 9 Submandibular area pain - 14DA

6 F 13 Thigh Pain &

swelling

+ 1DA

7 F 25 Knee Pain &

swelling

- 1DA

Change in VAS score during steroid

injection

0

1

2

3

4

5

6

7

8

9

10

initial Steroid #1 Steroid #2 Steroid #3 Steroid #4

VA

S s

core

Case

high-dose

corticosteroids

F/ 13 years , Rt. Knee pain & swelling, onset :1DA

Classes of medication

Class Ⅰ

• Short-term use of high-dose corticosteroids, and use of non-steroidal anti-inflammatory drugs (NSAIDs) including the new anti-inflammatory and anti-angiogenic cox-2 inhibitors

Class Ⅱ

• Leukotriene inhibitors, mast cell stabilizers, and aminobisphosphonates (Pamidronate; Zoledronate)

Class Ⅲ

• Signal transduction inhibitors, monoclonal antibodies targeting ACVR1, and retinoic acid receptor gamma agonists (presently under development).

(FOP Rx Guideline 2011, Kaplan)

Use of Corticosteroids

• Brief 4-day course of high-dose corticosteroids

; within the first 24 hours of a flare-up

1. The extremely early symptomatic treatment of flare-ups that affect: Major joints, jaw, submandibular area.

2. The prevention of flare-ups following major soft tissue injury (severe trauma).

3. The prevention of flare-ups in emergent, elective, and minor surgeries such as dental surgery, hypospadias repair, appendectomies, etc. (peri-operative use).

(Glaser & Kaplan, 2005 )

Use of Corticosteroids • Prednisone is 2 mg/kg/day (up to 100 mg), administered as a

single daily dose for no more than 4 days.

• In order to have the least suppressive effect on the

hypothalamic-pituitary-adrenal axis, the medication should be

given in the morning.

• High dose intravenous corticosteroid pulse therapy may be

considered, but must be performed with an inpatient

hospitalization to monitor for potentially dangerous side-effects

of hypertension.

Use of Corticosteroids

• When prednisone is discontinued, a non-steroidal anti-

inflammatory medication or cox-2 may be used symptomatically

for the duration of the flare-up.

• If the flare-up responds to the medication but recurs when the

prednisone is discontinued, a repeat 4-day course with a

subsequent 10-day taper can be considered.

Summary (FOP Rx Guideline 2011) 1. Within 24 hours of the onset of a flare-up.

2. Use for flare-ups on the Jaw, submadibular area, major joints. Do not use for flare-ups involving chest or back.

3. Prophylactically following major soft tissue trauma.

4. Peri-operative use: In emergent, elective, and minor surgeries such as dental surgery, hypospadias repair, appendectomies, etc.

5. Prednisone 2 mg/kg/day (up to 100 mg), administered as a single daily dose for no more than 4 days.

Conclusion

• The clinical management of FOP is focused in the

prevention of flare-ups.

• High dose glucocorticoids should be considered in the very

early treatment of acute flare-ups(within 24 hours).