case_images: PMC8079983_01
case_images: Dermatological and histopathological findings. (A) - Oral ulceration and dactylitis (black arrows) and skin rash observed during fever flares resembling erythema nodosum. (B) Hematoxylin-eosin staining of skin biopsy (punch) previously fixed in 10% neutral buffered formalin. 1 - (100x magnification): Septal panniculitis (black arrow) with foci of inflammatory cells extending into adjacent fat lobule (red arrow). 2 - (400x magnification): epidermal spongiosis and lymphocyte exocytosis with dyskeratotic cells (arrow) and interface dermatitis with vacuolar changes in the basal layer.
case_images: fimmu-12-586320-g001.jpg
case_images: PMC8079983_01_fimmu-12-586320-g001.jpg
case_images: f1
case_images: In her ninth month of life, the appearance of a diffuse painful skin eruption was noted, marked by nodules and plaques, erythematoedematous rash and infiltrate, resembling erythema nodosum ( Figure 1 ). A biopsied skin specimen from her left leg revealed septal panniculitis, thus confirming the clinical suspicion of erythema nodosum ( Figure 1 ).
case_images: Baseline laboratory findings and treatment response over time. (A) Laboratory findings at baseline (normal ranges in brackets) (B-D) CRP, hemoglobin and Immunoglobulin G over time during febrile episodes and at basal levels. Dashed lines indicate immunoglobulin replacement, 1: single shot, and 2: after monthly infusions. (CRP, C-reactive protein; SAA, serum amyloid A).
case_images: fimmu-12-586320-g002.jpg
case_images: PMC8079983_01_fimmu-12-586320-g002.jpg
case_images: f2
case_images: All relevant laboratory analyses are summarized in  Figure 2 .