Dermatology: Practical and Conceptual


Image Letter | Dermatol Pract Concept. 2025;15(1):4898 1

Psoriatic Isomorphic Response From Molluscum 
Contagiosum

Iswariya Jaganathan1, Dineshkumar Selvaraj1, Navya Donaparthi1, Debdeep Mitra1

1 Department of Dermatology, Command Hospital Air Force Bangalore, India

Citation: Iswariya J, Dinesh Kumar S, Navya D, Mitra D. Psoriatic Isomorphic Response From Molluscum Contagiosum. Dermatol Pract 
Concept. 2025;15(1):4898. DOI: https://doi.org/10.5826/dpc.1501a4898

Accepted: November 9, 2024; Published: January 2025

Copyright: © Iswariya et al. This is an open-access article distributed under the terms of the Creative Commons Attribution-
NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use, 
distribution, and reproduction in any medium, provided the original authors and source are credited.

Funding: None.

Competing Interests: None.

Authorship: All authors have contributed significantly to this publication. 

Corresponding Author: Dr. Iswariya J, MBBS, Department of Dermatology, Command Hospital Air Force Bangalore, India.  
E-mail: iswariyajaganathan@live.in 

Case Presentation

An 11-year-old girl with known history of psoriasis vulgaris 

presented complaining of a few asymptomatic skin-col-

ored raised lesions over both arms and shoulders appeared  

2 months before. More recently she noticed the development 

of itchy, flaky, erythematous patches over these areas. Clinical 

examination revealed few discrete skin-coloured umbilicated 

papules 0.3 x 0.3 cm in size over the left shoulder and the 

infraclavicular regions sourranded by discrete erythematous 

plaques with silvery-white scales. Dermoscopic examination 

of the psoriatic plaque revealed pinkish-white homogenous 

areas with white scales and regular dotted vessels (Figure 1).

Teaching Point

A clinical diagnosis of psoriatic isomorphic response surround-

ing the preexisting molluscum contagiosum was made (1).  

The patient was managed with needle extirpation of the 

molluscum contagiosum along with topical steroids for 

the  psoriatic plaques, which resulted in the resolution of 

symptoms. 



2 Image Letter | Dermatol Pract Concept. 2025;15(1):4898

References

1. Ji YZ, Liu SR. Koebner phenomenon leading to the formation 

of new psoriatic lesions: evidences and mechanisms.  Biosci 

Rep. 2019;39(12):BSR20193266. DOI:10.1042/BSR20193266. 

PMID: 31710084. PMCID: PMC6893164.

Figure 1. (A) Multiple discrete erythematous scaly plaques around the central umbilicated 

papules of molluscum contagiosum. (B) Close-up view of molluscum contagiosum (black 

star) with surrounding psoriatic plaque (black arrow). (C) Dermoscopy of the molluscum 

contagiosum showing a whitish yellow papule with homogenous amorphous structure in 

the center (white arrow). (D) Psoriatic plaque: pinkish white homogenous areas with white 

scales and regular dotted vessels (blue star).