TAKING A CLOSER LOOK AT THE SURFACE: A TODDLER WHO WOULD NOT BEAR WEIGHT ON HIS FOOT

Case Presentation: A 2-year-old male with atopic dermatitis presented with worsening eczema, induration, erythema, and inability to bear weight on his left foot. He was afebrile and had initially been diagnosed with cellulitis. He had been treated with 2 different oral antibiotics and was hospitalized due to presumed failure of oral antibiotics. On admission, the differential diagnosis was expanded to include osteomyelitis. After minimal improvement in the patient’s condition, dermatology, infectious diseases, and orthopedic surgery were engaged in the patient’s care. MRI of the left foot revealed significant soft tissue edema and a small subtalar joint effusion with no concerns for osteomyelitis Surgical intervention was deferred, and topical steroids were initiated, improving the erythema but not the induration.Following improvement with steroids, dermatology recommended a biopsy to evaluate for eosinophilic dermatitis. A biopsy was taken from the skin on the dorsum of the patient’s left foot and oral steroids were initiated. His symptoms improved allowing him to ambulate on his left foot. The biopsy revealed a diagnosis of spongiotic dermatitis with scattered eosinophils. The patient was discharged to complete an oral steroid course.

Discussion: Spongiotic dermatitis is a skin condition characterized by accumulation of fluid within the skin. The diagnosis is made histologically with the pathology showing intercellular epidermal edema. [1] Spongiotic reaction patterns can vary based on disease process. A subtype of spongiotic dermatitis, eosinophilic spongiosis, may be seen in atopic dermatitis. [2] Spongiotic dermatitis symptoms include erythema, induration, and intense pruritus. [3] Spongiotic dermatitis mimic other skin conditions, leading to diagnostic uncertainty, as in this case when spongiotic dermatitis mimicked cellulitis.Cellulitis is an infection of the skin’s deep dermis and subcutaneous tissue. [4] Cellulitis presents as inflammation of the skin with induration and erythema at the site of infection. Skin biopsy is not indicated in most cases of cellulitis excluding atypical presentations. When performed, the pathology identifies edema with diffuse neutrophilic infiltration. [5] Resolution of cellulitis-associated inflammation is expected within 3 days of treatment with narrow-spectrum antibiotics. Persistence beyond this period should raise concerns for resistant infectious causes and/or non-infectious conditions.

Conclusions: Spongiotic dermatitis may mimic other skin conditions, both noninfectious and infectious. This mimicry leads to diagnostic uncertainty. If patients with a history of atopy present with cellulitis and respond poorly to antibiotics consider broadening the differential diagnosis to include spongiotic dermatitis.