Case Presentation
A 52-year-old Filipino female presented with a 29-year history of a recurrent pruritic erythematous blisters which evolved into coalescent nodules and plaques on the lower extremities. She was previously treated with topical and intralesional steroid injection with partial resolution. Two of her siblings were affected with similar lesions. Upon physical examination, there were multiple erythematous to hyperpigmented prurigo-like lesions with excoriations on both distal legs, dorsum of feet and forearms. Nail dystrophy was noted on all toes (Figure 1, A and B). Histopathological examination showed a hyperkeratosis overlying an acanthotic epidermis associated with a cell-poor subepidermal blister and fibrotic changes with abundant blood vessels on the superficial dermis (Figure C). Direct immunofluorescence (DIF) results showed negative findings. Genetic testing of her blood samples revealed that the proband was compound heterozygous for a nonsense and another splice-site mutation in COL7A1. In silico splicing effect prediction of COL7A1: c.7485G>A indicates that COL7A1 protein translation may be affected. These results confirmed the diagnosis of epidermolysis bullosa (EB) pruriginosa.
Figure 1.
(A) Multiple erythematous to hyperpigmented prurigo-like lesions with linear excoriations on both distal legs and dorsum of feet associated with nail dystrophy on all toes. (B) A closer view of the prurigo-like linear lesions on the left leg. (C) Histopathology, H&E 4x. Cell-poor subepidermal blister.
Teaching Point
EB pruriginosa manifests as prurigo-like plaques and nodules with pruritus [1,2]. Histopathology findings of a subepidermal blister, negative DIF findings, and a COL7A1 mutation confirms the diagnosis [2]. We present a rare case which can be misdiagnosed as prurigo nodularis. However, the chronicity of the lesions, partial and temporary relief to topical and intralesional steroids, affectation of siblings, prompted further investigation. Histopathology, DIF studies and COL7A1 gene mutation confirmed the diagnosis of this rare and challenging case.
Footnotes
Funding: None.
Competing interests: None.
Authorship: All authors have contributed significantly to this publication.
References
- 1.Pai VV, Sori T, Naveen KN, Athanikar SB, Rai V, Shastry DU. Epidermolysis bullosa pruriginosa: A report of two cases. Indian Dermatol Online J. 2014;5(1):44–47. doi: 10.4103/2229-5178.126030. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Nijhawan M, Nijhawan Agarwal, Jhangra R, Goel P, Sehgal VN. Epidermolysis bullosa pruriginosa a Clinico -pathological study in an index case, highlighting its affliction in 11 of 27 member of the family. Journal of Dermatology & Dermatologic Surgery. 2017;21(2):100–103. doi: 10.1016/j.jdds.2017.04.002. [DOI] [Google Scholar]