“Hypopyon” sign in dermatology

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IJDVLIndian Journal of Dermatology, Venereology and LeprologyIJDVL0378-
63230973-3922Scientic Scholar
10.25259/IJDVL_654_2023
“Hypopyon” sign in dermatology
Mohammad Danish, Varniraj Mukeshbhai Patel, Vishal Gaurav
Department of Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India
Introducon
The “hypopyon sign” is a distinctive clinical manifestation
characterised by the presence of small, discrete vesicles that
can be either accid or tense. The vesicles initially contain
clear uid which subsequently becomes turbid and eventually
pustular, either due to intense neutrophilic inammation or
secondary bacterial infection, resulting in the accumulation
of pus, predominantly in the lower half, of the corresponding
pustules. When a patient exhibiting the hypopyon sign
assumes a standing position, a unique visual characteristic
becomes apparent. Within the pustule, a transverse uid level
can be observed, consisting of purulent material that settles
at the bottom. This uid level, positioned horizontally within
the pustule, is specically referred to as the hypopyon sign.1
This particular sign is commonly observed in two types of
conditions: pyodermas, which are infectious skin disorders
characterised by the presence of pus, and vesiculobullous
disorders. Examples of the latter include pemphigus, bullous
pemphigoid and linear IgA dermatosis.
The presence of the hypopyon sign serves as a valuable
clinical indicator of the severity of infection and inammation
in these conditions. Its identication aids in the diagnosis and
management of patients, providing crucial insights into the
extent of the disease and secondary bacterial infection and
the need for appropriate treatment interventions.
In this article, we aim to compile an extensive inventory
of dermatological conditions that are commonly and less
commonly associated with the presence of the hypopyon
sign. The identied conditions have been categorised into
two main groups: autoimmune/inammatory dermatoses
and infectious dermatoses. This comprehensive list aims to
provide a valuable resource for a better understanding and
recognition of dermatological disorders associated with the
hypopyon sign.
1. Autoimmune/inammatory dermatoses
a. Pemphigus vulgaris
Pemphigus vulgaris is characterised by accid
vesiculobullous lesions that rapidly rupture to
form painful erosions. In some cases, patients may
exhibit intact blisters where a collection of pus can
be observed at the base, distinctively separated
from clearer uid at the top. This characteristic
separation of uids within the blister is commonly
referred to as the “hypopyon sign” [Figure 1].2
b. Pemphigus foliaceous
Pemphigus foliaceous commonly presents with
itchy recurrent shallow erosions with crusting
and scaling, predominantly in a seborrheic
distribution. Occasionally, patients may have
intact blisters that contain sterile pus and as a
result of gravitational pull in dependent areas, the
pus settles in the lower half of the lesion leading to
the formation of a “hypopyon” [Figure 2].2
c. IgA pemphigus
IgA pemphigus is a rare autoimmune intra-
epidermal blistering disorder presenting as painful
and pruritic accid pustules on an erythematous
base that quickly ruptures to form erosions that
later develop crusting. Hypopyon sign has been
reported in IgA pemphigus.3
d. Paraneoplastic pemphigus
Paraneoplastic pemphigus is an autoimmune
blistering paraneoplastic condition characterised
by severe mucositis and variable cutaneous
manifestations. Hypopyon sign can be seen
How to cite this article: Danish M, Patel VM, Gaurav V. “Hypopyon” sign in dermatology. Indian J Dermatol Venereol Leprol. doi: 10.25259/IJDVL_654_2023
Corresponding author: Dr. Vishal Gaurav, Department of Dermatology and Venereology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi,
India. mevishalgaurav@gmail.com
Received: June, 2023 Accepted: September, 2023 EPub Ahead of Print: November, 2023
DOI: 10.25259/IJDVL_654_2023
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© 2023
Indian Journal
of Dermatology,
Venereology
and Leprology
- Published by
Scientific Scholar
2023Indian Journal
of Dermatology,
Venereology and
Leprology
This is an open-access article distributed under the terms
of the Creative Commons Attribution-Non Commer-
cial-Share Alike 4.0 License, which allows others to remix,
transform, and build upon the work non-commercially, as
long as the author is credited and the new creations are
licensed under the identical terms.

Danish, et al.“Hypopyon” sign in dermatology
Indian Journal of Der matology, Venereology and Leprology | November 20232
in paraneoplastic pemphigus due to intense
inammation.4
e. Bullous pemphigoid
Bullous pemphigoid represents a chronic
autoimmune blistering disorder aecting the
subepidermal layer. The cutaneous symptoms of
this condition are highly diverse, encompassing
both non-bullous and bullous phases. In the bullous
phase, tense vesicles or bullae typically appear on
urticarial plaques or unaected skin. These uid-
lled lesions which contain clear or haemorrhagic
uid, are often accompanied by itching. It is worth
noting that although rare, the presence of the
hypopyon sign may accompany the bullae in some
cases of bullous pemphigoid [Figure 3].2
f. Chronic bullous disease of childhood and linear
IgA disease
Chronic bullous disease of childhood is an
autoimmune blistering disease that primarily
aects children. Linear IgA represents an adult
variant of the disease. Characteristic lesions
include a cluster of jewel-like or annular
arrangement of vesicles, often involving the peri-
oral area. The bullae in chronic bullous disease of
childhood typically contain clear uid, although
there are instances where the lower half of the
blister may contain yellow uid resulting in a
distinct half-and-half appearance of the blisters.5
g. Sub-corneal pustular dermatosis
Sub-corneal pustular dermatosis, also known as
Sneddon–Wilkinson syndrome, is an uncommon
pustular dermatosis characterised by the presence
of sterile pustules presenting in a symmetrical
distribution pattern, often aecting the trunk,
intertriginous areas (particularly the axillae) and
exures of the upper and lower limbs. The pustular
eruption emerges as small pustules on a normal
or slightly erythematous base. A distinct visual
feature of these pustules is the presence of a clear
demarcation line dividing them horizontally into
two halves, the upper zone containing clear uid
and the lower zone containing yellowish-white
turbid uid. This gives rise to a characteristic
“half-half” appearance or a “hypopyon pustule”.6
Hypopyon sign is classically described with sub-
corneal pustular dermatosis.
h. Pustular psoriasis
Generalised pustular psoriasis presents with an
acute eruption characterised by multiple sterile
pustules on an erythematous and oedematous
background accompanied by systemic features.
In some cases, multiple pustules, especially
those located on the back in dependent positions,
exhibit a clear horizontal demarcation with pus
settling in the lower portion of the pustule giving
rise to a hypopyon. Although it may not be readily
apparent during a clinical examination, the
Figure 1: A 35-year-old woman with pemphigus vulgaris showing
accid bullae with “hypopyon” (blue arrow).
Figure 2: A young woman with pemphigus
foliaceous showing small supercial vesicles
with “hypopyon” (blue arrow).
Figure 3: A 40-year-old man with bullous pemphigoid showing
tense bulla with “hypopyon” (blue arrow).

Danish, et al.“Hypopyon” sign in dermatology
3Indian Journal of Der matology, Venereology and Leprology | November 2023
presence of this feature can be easily visualised
using a dermoscope [Figures 4a and 4b].7
i. Acute generalised exanthematous pustulosis
Acute generalised exanthematous pustulosis
presents with multiple small, sterile, non-follicular
pustules on an erythematous base with no or
minimal mucous membrane involvement. The
distribution favours the trunk and intertriginous
regions. Acute generalised exanthematous
pustulosis is typically pruritic. Some of the larger
pustules can show settling of pus in the lower
half of the lesion with a clear demarcation at
the horizontal level (hypopyon sign). Similar
to pustular psoriasis, these pustules may not be
discernible during a clinical examination due
to their small size. In such cases, the use of a
dermoscope may be necessary to accurately
visualise and evaluate them.8
2. Infections
a. Bullous impetigo
Bullous impetigo is a bacterial skin infection
primarily aecting infants and children, caused
by Staphylococcus aureus. It is characterised
by the presence of vesicles, bullae and crusted
erosions. The bullae in bullous impetigo are non-
sterile and exhibit a distinct appearance with
pus accumulating in the lower half of the lesion,
while the upper half contains clear uid, leading
to hypopyon formation. It can also be seen in
staphylococcal scalded skin syndrome [Figure 5].9
b. Varicella
Varicella-zoster virus infection, also known
as chickenpox, is characterised by generalised
small itchy vesicles on erythematous skin which
eventually scabs over time. The most common
complication is bacterial superinfection by
Staphylococcus aureus and supercial skin
infections. Vesicles of varicella can develop pus
leading to formation of pus-lled accid blisters
which can show a transverse uid level due to
accumulation of pus in the lower half (hypopyon
sign) [Figure 6].10
c. Cutaneous candidiasis
Cutaneous candidiasis is a fungal infection caused
by candida species that primarily aects the skin
and mucous membranes. It presents as red, itchy
rashes with satellite pustules, commonly occurring
in warm and moist areas of the body, such as skin
folds. These pustules have perilesional erythema.
It occurs more frequently in immunocompromised
individuals or neonates. In some instances, the
satellite pustules may exhibit the accumulation of
pus in the lower portion of the pustule, leading to
the formation of a hypopyon [Figures 7a and 7b].11
3. Miscellaneous
a. Lymphangioma circumscriptum
The “red” hypopyon sign, observed through
dermoscopy, is a notable characteristic of
lymphangioma circumscriptum. This sign refers
to the presence of red uid or blood settled at
the bottom of vesicles or lacunae, while the
upper portion contains clear or pale uid. It
indicates the presence of vascular congestion
or haemorrhage within the lymphatic vessels
[Figures 8a and 8b]. However, the term “red
hypopyon” is misleading because it describes
the presence of red uid or blood rather than the
presence of pus. The red hypopyon sign aids in
Figure 4a: A 25-year-old man with pustular psoriasis
showing a well-dened erythematous plaque with
overlying pustules.
Figure 4b: Dermoscopy showing micro-pustules with “hypopyon” (blue
arrow) (10×; polarised).

Danish, et al.“Hypopyon” sign in dermatology
Indian Journal of Der matology, Venereology and Leprology | November 20234
Figure 5: A 5-year-old girl with bullous impetigo
on the face showing multiple accid bulla with
“hypopyon” (blue arrows).
Figure 6: A 7-year-old boy with varicella showing a vesicle with “hypopyon”
(blue arrow).
Figure 7a: A 4-year-old boy with cutaneous candidiasis showing small
satellite pustules with peri-lesional erythema involving the neck fold.
Figure 7b: A 4-year-old boy with cutaneous candidiasis showing a tiny
vesicle with “hypopyon” (blue arrow).
Figure 8a: A 20-year-old man with lymphangioma circumscriptum showing
multiple clear uid-lled vesicles with “red-hypopyon”.
Figure 8b: Dermoscopy showing lacunae with “red-hypopyon” (blue arrow)
(10×, polarised).

Danish, et al.“Hypopyon” sign in dermatology
5Indian Journal of Der matology, Venereology and Leprology | November 2023
dierentiating lymphangioma circumscriptum
from other skin conditions and plays a crucial role
in its diagnosis.12
b. Cutaneous angiosarcoma
Angiosarcoma is a rare malignant tumour originating
from blood vessels. Cutaneous angiosarcomas can
be classically present over head and neck area or, be
linked to persistent lymphedema (Stewart-Treves
syndrome) or radiation-induced. Dermoscopy can
show “red hypopyon” in lymphedema-associated
angiosarcoma, possibly indicating an underlying
lymphatic stasis.13
Conclusion
The hypopyon sign can be observed in various conditions
including autoimmune/inammatory dermatoses such
as pemphigus vulgaris, pemphigus foliaceous, bullous
pemphigoid, chronic bullous disease of childhood and sub-
corneal pustular dermatosis as well as infectious dermatoses
like bullous impetigo and varicella. It indicates either
secondary infection or intense inammation within the
blisters.
Declaration of patient consent
The authors certify that they have obtained appropriate
patient consent.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conicts of interest.
Use of artificial intelligence (AI)-assisted technology for manuscript
preparation
The authors conrm that there was no use of articial
intelligence (AI)-assisted technology for assisting in the
writing or editing of the manuscript and no images were
manipulated using AI.
References
1. Madke B, Nayak C. Eponymous signs in dermatology. Indian Dermatol
Online J 2012;3:159–65.
2. Singh S, Gupta S, Chaudhary R. Hypopyon sign in pemphigus vulgaris
and pemphigus foliaceus. Int J Dermatol 2009;48:1100–2.
3. Cheng HF, Tsoi WK, Ng MMT, Ip WK, Ho KM. IgG/IgA pemphigus
with diering regional presentations. JAAD Case Rep 2022;28:
119–22.
4. Kekeç DÖ, Kaçar N, Demirkan NÇ. Hipopiyon belirtisi saptanan bir
paraneoplastik pemgus olgusu ve literatür incelemesi [A case of
paraneoplastic pemphigus with hypopyon sign and literature review].
Pam Med J 2018;11:81.
5. Pradhan S, Jha K, Kumari P, Shrestha S, Jha AK. Chronic bullous
disease of childhood: A case report and review of literature of bullous
diseases in children. Nepal J Dermatol Venereol Leprol 2022;20:
69–75.
6. Bhargava S, Kumar U, Kroumpouzos G. Subcorneal pustular
dermatosis: Comprehensive review and report of a case presenting
during pregnancy. Int J Womens Dermatol 2020;6:131–6.
7. Chandwar K, Dogga P, Dixit J, Ekbote D, Sahoo RR, Wakhlu A. Half-
lled or half-empty: Conundrum of “Hypopyon Sign” in pustular
psoriasis. Indian J Rheumatol 2022;17:318–9.
8. Sussman M, Napodano A, Huang S, Are A, Hsu S, Motaparthi K.
Pustular psoriasis and acute generalized exanthematous pustulosis.
Medicina (Kaunas) 2021;57:1004.
9. Amrani A, Sil A, Das A. Cutaneous signs in infectious diseases. Indian J
Dermatol Venereol Leprol 2022;88:569–75.
10. Gorris A, Weiss D, Kogler H, Szépfalusi Z, Karlhofer F, Handisurya A.
Hypopyon sign as an unusual complication of varicella infection in a girl
with atopic dermatitis. Wien Med Wochenschr 2021;171:61–4.
11. Taudorf EH, Jemec GBE, Hay RJ, Saunte DML. Cutaneous candidiasis:
An evidence-based review of topical and systemic treatments to inform
clinical practise. J Eur Acad Dermatol Venereol 2019;33:1863–73.
12. Gencoglan G, Inanir I, Ermertcan AT. Hypopyon-like features:
New dermoscopic criteria in the dierential diagnosis of cutaneous
lymphangioma circumscriptum and haemangiomas?. J Eur Acad
Dermatol Venereol 2012;26:1023–5.
13. Bostancı S, Akay BN, Vural S, Ertop P, Heper AO. Hypopyon sign
in dermatoscopy of cutaneous angiosarcoma. Australas J Dermatol
2019;60:e366–e368.