Dermatology Online Journal

Eosinophilic pustular folliculitis in infancy: Report of a new case
L Alonso-Castro¹ MD, B Pérez-García¹ MD PhD, C González-García² MD, P Jaén-Olasolo¹ MD PhD
Dermatology Online Journal 18 (10): 6

1. Servicio de Dermatología
2. Servicio de Anatomía Patológica
Hospital Ramón y Cajal, Madrid, Spain

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Abstract

We report a new case of eosinophilic pustular folliculitis in a 23-month-old boy. He presented with a seven-month history of recurrent episodes of pustular lesions on the scalp after having been treated with oral antifungal and topic antibiotics without response. The diagnosis was based on the clinical course and typical histopathological findings. Eosinophilic pustular folliculitis in infancy is an idiopathic and rare inflammatory disease characterized by recurrent crops of sterile pustules involving mainly the scalp. Because it is a benign, self-limiting condition an accurate diagnosis is essential to avoid unnecessary therapies.

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Introduction

Eosinophilic pustular folliculitis (EPF) in infancy was first described by Lucky in 1984 [1] as a distinct variant of the adult form previously described by Ofuji in 1970 [2]. EPF is a rare inflammatory disease of unknown etiology characterized by recurrent crops of sterile pustules involving mainly the scalp. We report a new case of EPF in infancy with typical clinical course and histopathological findings.

Case report

Figure 1	Figure 2
Figure 1. Clustered pustules on the scalp Figure 2. Perivascular and perifollicular infiltrate in the dermis (H&E x2)

Figure 3
Figure 3. Spongiosis of the follicular epithelium associated with an eosinophil-rich abscess (H&E x10)

A 23-month-old boy presented with a seven-month history of recurrent episodes of pustular lesions on the scalp. These lesions were intensely pruritic and lasted between 2 and 3 weeks with intermittent remissions. He had been treated with oral griseofulvin without response. Topical mupirocin and corticosteroids had been used in previous episodes with transitory improvement. The patient was otherwise healthy and had no family history of similar lesions.

At his first visit, the physical examination showed clustered pustules and crusts surrounded by erythema located on the parietal scalp. He also presented with isolated, erythematous and crusted papules on the trunk and face. Repeated swabs for bacterial and fungal culture were negative. Laboratory tests, including blood cell count and biochemistry, showed peripheral eosinophilia (2.400/mm³) with no other pathological findings.

With a suspected diagnosis of eosinophilic pustular folliculitis a 4 mm punch biopsy from a pustular lesion on the scalp was performed. The histopathological examination showed a cellular infiltrate with a follicular and perifollicular pattern in the dermis. The inflammatory infiltrate was composed predominantly of eosinophils with microabscess formation within the follicle and spongiosis of the follicular epithelium. In addition to eosinophils, there were some neutrophils and mononuclear cells. Periodic acid-Schiff (PAS) and silver methenamine stains did not identify fungal structures or other pathogens. The immunohistochemical study for CD1a was negative. These findings were consistent with eosinophilic pustular folliculitis of infancy.

The patient began treatment with topical corticosteroids and oral antihistamines during the flares with good clinical response.

Discussion

Eosinophilic pustular folliculitis is an idiopathic and rare condition characterized by the presence of follicular papules and sterile pustules with abundant eosinophils. Classic EPF is mainly found in Japanese adults and manifests as recurrent annular plaques with clusters of sterile follicular papules and pustules affecting the face, trunk, and limbs [3]. Two additional types have been described, the immunosuppression-associated EPF, which is the most common variant (most cases in patients with HIV) and the infantile EPF [4, 5].

The infantile variant presents in the first months of life, although the onset has been described from the first 24 hours of life to 3 years [6]. Boys are more frequently affected than girls. This entity is characterized by recurrent crops of papules and pustules located most commonly in the scalp, but scattered lesions may appear in face, neck, trunk and extremities. Lesions heal without scarring in 1 to 4 weeks. In 50 to 70 percent of the reported cases peripheral eosinophilia has been documented during active disease [7]. The disease spontaneously remits after a total duration of 3 months to 5 years.

The differential diagnosis includes bacterial folliculitis, dermatophyte infections, or herpes simplex. Scabies should be considered in cases with disseminated lesions. Negative cultures are required to exclude infectious etiologies [6]. Infantile acropustulosis is characterized by pruritic vesicles and pustules on the hands and feet, but occasionally on the scalp, face, and trunk. The histology demonstrates a non-follicular, mainly neutrophilic infiltrate [8]. When the disease occurs in the neonatal period, the differential diagnosis must include erythema toxicum neonatorum, transient neonatal pustular melanosis and Langerhans cell histiocytosis. The clinical features, course, and histology allow the exclusion of these disorders [9].

Although EFP in infancy is a benign, self-limited condition, topical corticosteroids and oral antihistamines, such as cetirizine [3], may be effective at reducing the pruritus and duration of flares. Other alternative treatments reported are oral erythromycin, penicilin G, and dapsone [3, 6].

Clinicians should be aware of this disorder to reassure parents and avoid prescribing unnecessary therapies.

References

1. Lucky AW, Esterly NB, Heskel N, et al. Eosinophilic pustular folliculitis in infancy. Pediatr Dermatol. 1984;1:202-206. [PubMed]

2. Ofuji S, Ogino A, Horio T, et al. Eosinophilic pustular folliculitis. Acta Derm Venereol. 1970;50:195-203. [PubMed]

3. Larralde M, Morales S, Santos Muñoz A, Lamas F, Schroh R, Corbella C. Eosinophlic pustular folliculitis in infancy: report of two new cases. Pediatr Dermatol 1999;16:118-120. [PubMed]

4. Nervi SJ, Schwartz RA, Dmochowski M. Eosinophilic pustular folliculitis: a 40 year retrospect. J Am Acad Dermatol. 2006;55:285-9. [PubMed]

5. Ziemer M, Böer A. Eosinophilic pustular folliculitis in infancy: not a distinctive inflammatory disease of the skin. Am J Dermatopathol. 2005;27:443-55. [PubMed]

6. Taïeb A, Bassan-Andrieu L, Maleville J. 4. Eosinophilic pustulosis of the scalp in childhood. J Am Acad Dermatol. 1992;27:55-60. [PubMed]

7. Coulson IH, Ling TC, Stringfellow HF. Case 2. Infantile eosinophilic pustular folliculitis (IEPF). Clin Exp Dermatol. 2002;27:80-1. [PubMed]

8. Aquino LL, Wu JJ, Dyson SW, Metz BJ. Erythematous papules and pustules on the scalp. Pediatric Dermatology 2009;26: 195-6. [PubMed]

9. Buckley DA, Munn SE, Higgins EM. Neonatal eosinophilic pustular folliculitis. Clin Exp Dermatol 2001; 26: 251-255. [PubMed]

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