SUDDEN ONSET PURPURA IN A HEALTHY INFANT: ACUTE HEMORRHAGIC EDEMA OF INFANCY

Sir,

Acute hemorrhagic edema of infancy (AHOI) is a rare form of small vessel vasculitis found in infants, which is often confused with Henoch-Schonlein Purpura (HSP). It is also known as Seidlmayer syndrome, purpura en cocarde avec oedeme, post-infectious cockade purpura and Finkelstein disease.[1,2] No such reported case from Indian subcontinent was found on performing Medline search, indicating the rarity of the disease in Indian population.

We report a case of 1.5 year old breast fed male child brought to casualty by the parents with complaints of multiple dark red lesions over bilateral upper and lower extremities and ears with swelling of legs since a day. He also had history of vomiting and intermittent low grade fever. There was no history of abdominal pain, joint pain, upper respiratory tract infection or recent immunization. The mother gave history of taking tablet Indomethacin for 4 days prior to development of rash in the child. On clinical examination, he had multiple round purpuric patches over both the extremities and bilateral ears with complete sparing of trunk [Figures 1 and 2]. He also had non-pitting edema over both the feet. There was no evidence of mucosal involvement, joint or abdominal tenderness. The initial diagnosis of drug-induced erythema multiforme was thought and the child was treated with oral antihistamines and prednisolone in adequate doses and the mother was advised to stop analgesics.

Figure 1.

Purpuric lesions on the buttocks and extremities, with sparing of trunk

Figure 2.

Targetoid purpura on the leg of the patient

The patient continued developing similar lesions. The hematological and biochemical parameters and urine examination did not show any abnormality. The histopathology from the purpuric lesion showed the presence of fibrinoid necrosis of vessel wall with perivascular neutrophilic infiltrate and leukocytoclasia suggestive of leukocytoclastic vasculitis [Figure 3]. The Direct immunofluorescence was negative for IgG, IgM, IgA, C3 and fibrin. Oral corticosteroids and antihistamines were stopped and syrup Amoxicillin was prescribed. He followed up after 7 days with complete subsidence of older lesions leaving behind hyperpigmentation and no evidence of new lesions [Figure 4]. Thus, the presence of purpuric lesions in an otherwise healthy child with a histopathology suggestive of leukocytoclastic vasculitis, unresponsive to oral steroids and antihistamines, led us to final diagnosis of AHOI.

Figure 3.

Histopathology of a purpuric lesion, showing fibrinoid necrosis of vessel wall with perivascular neutrophilic infiltrate and leukocytoclasia in the dermis suggestive of leukocytoclastic vasculitis (H and E stain, 40×)

Figure 4.

Complete subsidence of lesions after 7 days leaving behind post-inflammatory hyperpigmentation

AHOI is a rare form of leukocytoclastic vasculitis localized to skin, found in infants aged between 4 months and 2 years.[2] It was initially considered as an infantile variant of HSP but was later recognized as a distinct entity, based on several distinctive clinical and prognostic features. Although the exact etiology is unknown, the history of upper respiratory tract infection, drug intake or immunization is often elicited in 75% cases.[2] There have been reports of its association with cytomegalovirus infection[3,4] and Wiskott-Aldrich syndrome[1] also. Sudden appearance of sharply demarcated, annular, coin-shaped, targetoid purpuric lesions, limited almost entirely to the face and limbs and often accompanied by edema of face, scrotum and extremities and low grade fever are the characteristic features of the disease. The mucosa is always spared. Extracutaneous involvement may occur in the form of glomerulonephritis, abdominal pain, and arthralgias in less than 10% of cases.[4] Otitis, tonsillitis, rhinopharyngitis and gastroenteritis may also be associated.[5] The disease usually lasts for 1-3 weeks with no persistent effects or sequelae following resolution. During this period, lesions may fade and reappear several times.

Laboratory findings include mild leukocytosis, lymphocytosis, thrombocytosis, eosinophilia or high erythrocyte sedimentation rate.[2] However, there have been reports of abnormal renal function tests in the form of microscopic hematuria, proteinuria, abnormal liver function tests such as elevated serum transaminases and hypocomplementemia affecting C4, C1q and CH50 in patients with AHOI.[5,6] The histopathology shows fibrinoid necrosis of vessel wall, extravasation of red blood cells, perivascular neutrophil accumulation and leukocytoclasia, suggestive of leukocytoclastic vasculitis. Immunofluorescence may or may not show vascular IgA, IgM, C3 or C1q deposits.

It has to be distinguished from HSP, urticarial vasculitis and erythema multiforme. HSP is characterized by later age of onset, papulo-petechial lesions mainly over lower extremities, frequently accompanied by visceral involvement and IgA depositions on immunohistopathology but absence of C1q positivity.[2,4,6] Erythema multiforme does not show features of leukocytoclastic vasculitis. Urticarial vasculitis presents as wheals that persist longer and it has a chronic course with frequent exacerbations and remissions.

No specific treatment is required as the disease is self-resolving with no adverse sequelae. However, systemic antibiotics should be given to combat infection and end further antigenic stimulation.[2] Systemic corticosteroids and anti-histamines do not alter the disease course.

AHOI is thus a well-localized, self-resolving disease of acute onset with excellent prognosis. Pediatricians and dermatologists should be familiar with the disease to avoid misdiagnosis of HSP which is rather a severe disease with extensive visceral involvement, and thus save patients from unnecessary investigations and treatment.