You are correct. Histology demonstrated surface excoriation and focal erosion with underlying dense monomorphous histiocytic population and abundant eosinophilic infiltration, confirming the dx of giant juvenile xanthogranuloma. It typically presents before age 1, with lesions often described as yellow papules with a “setting sun” appearance.

Tx options include observation for self-involution and surgical excision. Generally, surgical management is reserved for symptomatic lesions, as this may result in scarring, local infection, and in some cases, recurrence.

Three months later, signs of spontaneous regression in this patient were observed.

Archives of Disease in Childhood 2022;107:905

You are correct. Oculomotor nerve palsy is a clinical dx heralded by ipsilateral ptosis, ophthalmoplegia, diplopia, mydriasis, and impaired pupillary light reflex. Etiologies include diabetic peripheral neuropathy and painful ophthalmoplegia, although intracranial aneurysm is the leading cause.

After the physical exam, the patient had a sudden-onset general-tonic seizure. Emergent cranial CT showed diffuse subarachnoid hemorrhage and ruptured posterior communicating artery. The patient underwent emergent external ventricular drainage and clipping of the aneurysm. She was discharged in stable condition 10 weeks later.

Due to the peripherally located pupillary fibers on the third nerve, the pupil is highly sensitive to compression. Ptosis combined with headache, diplopia, and pupillary involvement should prompt consideration of a posterior communicating artery aneurysm, which may be fatal.

Myasthenia gravis may present with ptosis and ophthalmoparesis but not pupillary involvement. Horner syndrome results in myosis, partial ptosis, anhidrosis, and apparent enophthalmos on the affected side of the face.

Emergency Medicine Journal 2023;40:19-55

You are correct. Anti-histidyl tRNA synthetase was positive at 182 UR/mL (<20). The patient fulfilled the proposed criteria by Connors (2010) and Solomon (2011) for antisynthetase syndrome: positive antisynthetase antibodies, myositis, interstitial lung disease (ILD), arthritis, fever, and “mechanic’s hands” (nonpruritic and hyperkeratotic erythema on the sides of the digits). The classic triad (myositis, arthritis, and ILD) is present in only 20% of patients at disease onset. Other manifestations include fever and Raynaud syndrome.

An extended myositis antibody panel—an ELISA that includes anti-MDA-5, anti-PMScl, and anti-Ku—can help r/o other myositis-specific and associated autoantibodies. NL levels of C3/C4 complement, anti-dsDNA antibodies, and rheumatoid factor would make the dx of systemic lupus erythematosus and RA unlikely. Fever and mechanic’s hands are useful clues in the DDx of autoimmune myopathy and increase the possibility of antisynthetase syndrome.

Tx with prednisolone and cyclophosphamide improved the patient’s weakness and dyspnea at 6-month follow-up, without recurrence.

BMJ 2022;379:e072171