Method
Upon presentation of the patients with tender, erythematous nodules on
the lower extremities, a comprehensive differential diagnosis was
considered. The differential diagnosis for EN includes infectious causes
(e.g., streptococcal infections, tuberculosis, Yersinia, Mycoplasma,
Chlamydia, Histoplasma, Coccidioides, and HIV), inflammatory conditions
(e.g., sarcoidosis, inflammatory bowel disease, and Behçet’s disease),
malignancies (e.g., lymphoma, leukemia, and solid tumors), medications
(e.g., oral contraceptives, sulfonamides, and certain antibiotics), and
other causes (e.g., pregnancy, Sweet’s syndrome, and idiopathic EN).
A thorough clinical evaluation and targeted laboratory investigations
were conducted to establish the diagnosis and identify the underlying
cause of EN in this familial cluster. Physical examination included a
detailed assessment of the skin lesions, their distribution, size,
color, and tenderness, as well as a comprehensive systemic examination
to detect any associated signs or symptoms. Laboratory tests included a
complete blood count to evaluate for leukocytosis, ASO titers to detect
recent streptococcal infection, ESR and CRP levels to assess underlying
inflammation, and renal and hepatic function tests to rule out systemic
involvement. Imaging studies, such as chest radiographs, were performed
to screen for pulmonary involvement or associated conditions, and PCR
tests for COVID-19 were conducted to exclude this as a potential cause.
Although not performed in this case, a deep incisional or excisional
biopsy of the nodules may be considered to confirm the diagnosis of EN
and exclude other nodular lesions.
The management of EN in this familial cluster focused on providing
supportive care to alleviate symptoms, as the patients were referred to
the doctor after the optimal window for initiating antibiotic therapy
had passed. Due to the late presentation, the golden time for antibiotic
initiation had ended, precluding the use of antibiotics to treat the
underlying streptococcal infection. Supportive measures included rest,
leg elevation to reduce swelling and discomfort, nonsteroidal
anti-inflammatory drugs (NSAIDs) to manage pain and inflammation, and
cool compresses applied to the affected areas to provide symptomatic
relief. Close follow-up was ensured to assess the response to these
supportive measures, monitor for potential complications, and evaluate
for any underlying systemic diseases, particularly in the setting of
familial EN. Although antibiotics are typically the mainstay of
treatment for EN secondary to streptococcal infection, the delayed
presentation in this case necessitated a focus on symptom management and
supportive care.