DermNet provides Google Translate, a free machine translation service. Note that this may not provide an exact translation in all languages

Translate

Epidermolysis bullosa pruriginosa

Author: Dr Stephanie Ball, Dermatology Registrar, Royal Infirmary of Edinburgh, Scotland. Chief Editor: Hon A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand, October 2015. DermNet NZ Revision September 2021


Epidermolysis bullosa pruriginosa — codes and concepts
open

What is epidermolysis bullosa pruriginosa?

Epidermolysis bullosa pruriginosa (OMIM 604129) is a rare and clinically heterogeneous form of dystrophic epidermolysis bullosa (dystrophic EB), resulting from a mutation in the type VII collagen gene.

First described in 1994, there have been fewer than 100 cases documented in the literature, and as such, little is known about the condition or its treatment.

Who gets epidermolysis bullosa pruriginosa?

Epidermolysis bullosa (EB) pruriginosa can either present shortly after birth, or in adulthood.

  • In neonates, EB pruriginosa usually presents as blistering on the peripheral limbs. The blistering may either continue or temporarily resolve in infancy.
  • During adolescence or early adulthood, patients with EB pruriginosa develop pruritic lichenified plaques that persist long term. The initial presentation may be delayed until the second or third decade of life.

What causes epidermolysis bullosa pruriginosa?

As with other forms of dystrophic EB, the clinical findings of EB pruriginosa are attributed to mutations in the COL7A1 gene on chromosome 3p21.3, which encodes type VII collagen. Case reports of epidermolysis bullosa pruriginosa reveal many different alterations to this gene, including missense, nonsense, frame shift, and splice-site mutations.

Type VII collagen is a major skin structural component of the anchoring fibrils at the dermo-epidermal junction (DEJ). Mutations in the coding gene hamper the function of the anchoring fibrils and lead to a split in the DEJ below the level of the lamina densa. Clinically, this manifests as trauma-induced blisters, which heal leaving a scar.

Inheritance is variable; autosomal dominant and autosomal recessive patterns of inheritance have been reported. Most cases however have been found to be sporadic.

The characteristic pruritic component of the condition is poorly understood. A raised serum IgE level has been found in 7 of 9 examined patients with epidermolysis bullosa pruriginosa, and in some cases was found to be over 3 times the upper limit of normal. However, a personal or family history of atopy was a confounding factor in three of these patients, and so the results are far from conclusive.

What are the clinical features of epidermolysis bullosa pruriginosa?

EB pruriginosa is characterised by intensely itchy (pruritic) hypertrophic papules, nodules, and plaques usually on the lower extremities.

  • Excoriations
  • Violaceous lichenified lesions
  • Usually linear pattern
  • Prurigo-like lesion with scarring and milia
  • Pretibial (shin) involvement is typical; can involve forearms and trunk
  • Face, neck, and flexures are spared
  • Nail dystrophy is common

What are the complications of epidermolysis bullosa pruriginosa?

What is the differential diagnosis of epidermolysis bullosa pruriginosa?

How is epidermolysis bullosa pruriginosa diagnosed?

Epidermolysis bullosa pruriginosa should be considered clinically based on family history, clinical features, and a positive mechanobullous history, and confirmed with investigations.

  • Light microscopy of skin biopsy
    • hyperkeratosis, acanthosis, disruption of the dermo-epidermal junction forming a subepidermal blister, milia, prominent dermal and perivascular lymphohistiocytic infiltrate
  • Direct immunofluorescence on skin biopsy - negative
    • useful to exclude other blistering conditions
  • Electron microscopy
    • confirms the level of the split
    • diminished or absent anchoring fibrils in the sub-lamina densa
  • Genetic testing
    • COL7A1 mutations 

What is the treatment of epidermolysis bullosa pruriginosa?

General measures

  • Avoid trauma
  • Protective clothing
  • Wound care

Topical treatment of itch

Systemic treatment

Success has been varied and many treatments have been reported for a single case. Sustained responses has been recently reported with dupilimab.

What is the outlook for patients with EB pruriginosa?

Little is known about the long-term outcome for patients with EB pruriginosa. It is lifelong and often refractory to treatment. 

No long term data exists with regards to the sustainability of medication-induced remission.

See smartphone apps to check your skin.
[Sponsored content]

 

Related information

 

References

  • Banky JP, Sheridan AT, Storer EL, Marshman G. Successful treatment of epidermolysis bullosa pruriginosa with topical tacrolimus. Arch Dermatol. 2004;140(7):794-6. doi:10.1001/archderm.140.7.794 Journal 
  • Clawson RC, Duran SF, Pariser RJ. Epidermolysis bullosa pruriginosa responding to dupilumab. JAAD Case Rep. 2021;16:69-71. Published 2021 Aug 18. doi:10.1016/j.jdcr.2021.07.036 PubMed Central
  • Kim WB, Alavi A, Walsh S, Kim S, Pope E. Epidermolysis bullosa pruriginosa: a systematic review exploring genotype-phenotype correlation. Am J Clin Dermatol. 2015;16(2):81-7. doi:10.1007/s40257-015-0119-7 PubMed
  • Kim WB, Alavi A, Pope E, Walsh S. Epidermolysis bullosa pruriginosa: case series and review of the literature. Int J Low Extrem Wounds. 2015;14(2):196-9. doi:10.1177/1534734615572469 PubMed 
  • McGrath JA, Schofield OM, Eady RA. Epidermolysis bullosa pruriginosa: dystrophic epidermolysis bullosa with distinctive clinicopathological features. Br J Dermatol. 1994;130(5):617-25. doi:10.1111/j.1365-2133.1994.tb13109.x PubMed 
  • Mellerio JE, Ashton GH, Mohammedi R, et al. Allelic heterogeneity of dominant and recessive COL7A1 mutations underlying epidermolysis bullosa pruriginosa. J Invest Dermatol. 1999;112(6):984-7. doi:10.1046/j.1523-1747.1999.00614.x Journal 

On DermNet NZ

Other websites

Books about skin diseases

See the DermNet NZ bookstore.

Sign up to the newsletter