The spectrum of histopathologic findings in cutaneous eruptions associated with influenza A (H1N1) infection

Abstract

Influenza A (H1N1), like many other viral infections, has been associated with cutaneous eruptions. Differential diagnoses in a viral exanthem generally include spongiotic dermatitis, urticaria and drug reaction. The aim of this series was to retrospectively review three cases (five biopsies) involving patients with a clinical history of H1N1 and an accompanying rash, and to evaluate whether unique histopathologic and immunohistochemical features exist among these patients' cutaneous eruptions. Findings among all cases included a sparse superficial perivascular infiltrate, and interestingly, scattered interstitial and prominent intravascular neutrophils. Two cases demonstrated mild spongiosis and mild interface change. Immunohistochemistry in all cases revealed a CD4-predominant lymphocytic infiltrate of the dermis with a sparse intraepidermal population of admixed CD4 and CD8 positive lymphocytes. Many changes found in the cutaneous eruption associated with H1N1 are similar to those of other viral eruptions, including a mild perivascular lymphocytic infiltrate, mild spongiosis and mild interface change; however, sparse dermal and intravascular neutrophils and intraepidermal lymphocytes appear to be the features unique to these cases of H1N1-associated cutaneous eruptions. Such a distinction may prove diagnostically important in the clinical setting and useful in the surveillance of this historically pandemic virus.

Interferon‐beta as an enhancer of paraviral exanthema during influenza virus infection

“…(a) clinical aspect (abdomen) during first visit/+4 days, (b) clinical aspect (left thigh)/+7 days (captured by the patient), (c) clinical aspect (abdomen) during follow-up visit/ +12 weeks exanthema during influenza exist. 3 Interestingly, the distribution pattern of our patient's rash suggests IFN-b injections as a trigger of immune response. The mechanisms involved in paraviral exanthema are not fully unravelled, yet.…”

“…1,2 DF is a chronically relapsing disease with keratotic papules especially in seborrhaeic areas with tendency to superinfections and malodours. 3 Treatment, such as antiseptics, antibiotics, corticosteroids and retinoids, does not result in cure. 3 Superficial radiotherapy (SR) uses low-energy X-rays (20-100 kV) to kill cells by ionization of atoms.…”

Case series of rash associated with influenza B in school children

“…Among adult Singaporean military recruits, rash (undescribed) was more often associated with influenza A/H3N2 than A(H1N1) pdm09 or influenza B . Rash associated with influenza A has been variously characterized as petechial, macular, papular, maculopapular, reticular or purpuric and has been localized, multifocal or generalized, pruritic and non‐pruritic . Generalized maculopapular rash associated with influenza A(H1N1) pdm09 spared the palms and soles, as was also noted here for influenza B …”

Viral exanthems

“…Although rash is uncommon in influenza, cutaneous manifestations have been reported with influenza A (H1N1)pdm09, A/H7N9 and influenza B [50][51][52][53]. A confluent maculopapular rash that spares the face and palmoplantar surfaces has been observed in influenza A (H1N1)pdm09 infection [51].…”