Palmoplantar Pseudovesicles: An Unusual Presentation of Sweet's Syndrome.

Sir,

Sweet's syndrome (SS) is the prototypical neutrophilic dermatosis also known as acute febrile neutrophilic dermatosis or Gomm Button disease, was originally described by Dr Robert Douglas Sweet in 1964. Classically SS is characterized by pyrexia which usually precedes the onset of cutaneous manifestation of the disease. Skin lesions of SS are typically tender, purple red edematous papules and nodules which give an illusion of vesiculation. The eruption favors the head, neck and the upper extremities with an asymmetric distribution. Other symptoms associated with SS include arthralgia, malaise, headache and myalgia. SS characterized with new clinical associations and unusual clinical variants have aroused much interest and discussion recently.[1] SS localized to the hands has been described as a rare dermatosis first by Galaria et al.[2] under the entity neutrophilic dermatosis of the dorsal hands. Subsequent reports of similar cases have been reported in the literature by Takahama et al.[3] and Cook et al.[4] Involvement of the palms and soles as the only finding in SS is a rarity. Till date only one case of palmoplantar involvement in SS has been reported by Sommer et al.[5]

Diagnostic criteria for SS include, major criteria: (1) abrupt onset of typical cutaneous lesions and (2) histopathology consistent with SS. Minor criteria: (1) lesions preceded by one of the associated infections or vaccinations, accompanied by one of the associated malignancies or inflammatory disorders associated with drug exposure or pregnancy; (2) presence of fever and constitutional signs and symptoms; (3) leukocytosis and (4) excellent response to systemic corticosteroids. (At least 2 major and 2 minor criteria are needed to diagnose a patient with SS).

Our patient was a 47-year-old female who presented to the Department of Dermatology with complaints of abrupt onset of slightly raised erythematous non tender skin lesions over the palms and the soles for the past 1 week. The lesions rapidly increased in size to reach the current status. There were no associated systemic symptoms. Her medical and family history was non-contributory. She was receiving no medications. She had no underlying disease such as hematologic malignancy, or inflammatory bowel disease. She was afebrile with no pallor. Physical examination revealed erythematous, edematous plaques over the finger tips and also involving the hypothenar eminences in a symmetrical pattern [Figure 1]. Over both the soles the plaques were more edematous than the palms mainly involving the medial aspect in a symmetrical pattern and giving an illusion of vesiculation [Figures 2 and 3]. A biopsy specimen taken from the lesion showed no epidermal changes. The dermis showed a diffuse nodular and perivascular neutrophilic infiltrate without evidence of vasculitis [Figures 4 and 5]. The laboratory studies revealed a normal erythrocyte sedimentation rate. Her white blood cells count was 13,000 cells/mm3 with 80% neutrophils. Her peripheral smear was normal. The hemoglobin level was 13 gm/dL and the platelet count was 200,000 cells/mm3. The result of serum electrolyte assessment, the renal and liver function panel and the urinalysis were normal. An ultrasound of the abdomen and pelvis showed no underlying abnormality. Based on the clinical and laboratory findings a diagnosis of SS was made. The patient was started on 20 mg of Prednisolone once daily for 2 weeks and 0.5 mg of Colchicine twice daily for 2 weeks. The lesions resolved without scarring. The patient was subsequently lost to follow up.

Figure 1

Erythematous and edematous plaques involving the finger pulps and the hypothenar eminences in a bilateral symmetric distribution

Figure 2

Medial aspect of both the soles involved in a bilaterally symmetrical manner with the characteristic psuedovesiculation

Figure 3

Closer view demonstrating the psuedovesicles

Figure 4

Low power view of the dense inflammatory dermal infiltrate around the blood vessels and also diffusely distributed

Figure 5

Dense neutrophilic infiltrate made out on high power without any evidence of vasculitis

SS can have a very rare presentation as highlighted in our patient. Apart from the palmoplantar involvement there were no other cutaneous findings in our patient. A bilateral symmetrical presentation, a localized involvement, absence of constitutional symptoms and asymptomatic cutaneous lesions should not deter us from keeping a diagnosis of SS in mind because of the unusual manner in which this disorder may sometimes present.