Atypical Presentation of Sweat Dermatitis with Review of Literature

Abstract

Sweat dermatitis is a peculiar kind of irritant inflammatory dermatoses occurring due to prolonged exposure of retained sweat over the skin. It is commonly seen in hot and dry climates like tropics during summer months due to thermal stress. Typically, parchment paper or cellophane paper like scaling is seen over occluded areas of back, shoulder, and other areas. Here we have reported a varied presentation of sweat dermatitis in the form of its coexistence with miliaria rubra (impending to thermal burn). Further we have also observed co existing pityriasis versicolor and sweat dermatitis where the former has prevented the development of latter. Till date there is very little discussion on this condition, so we have tried to provide a concise review about sweat dermatitis along with its classical to atypical presentation with special emphasis on dermoscopy.

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698 © 2019 Indian Dermatology Online Journal | Published by Wolters Kluwer - Medknow
Introduction
India, being a tropical country has a
variable temperature ranges at different
places. In a metro city of Delhi, average
temperature of 44–45°C with low humidity
is generally recorded in the months of
May and June. Such climatic conditions
leads to profuse sweating which is further
aggravated by outdoor activities, traveling
for longer durations, overcrowding,
prolonged working in ill‑ventilated places,
etc.[1] Sweat has an important role in body
temperature regulation but sometimes
due to adverse climatic conditions like
high air temperature and high humidity,
leading to high heat index, the excess
sweat produced by the body does not get
completely evaporated, and leads to sweat
stagnation. Under occlusive conditions this
excessive sweat can cause irritant reaction
and dermatitis like clinical picture. In the
last few months, we have observed many
cases of this sweat‑induced dermatitis with
varied clinical presentations. Out of these, a
prototype and 2 atypical cases are described
here, and the literature reviewed of this
interesting dermatosis.
Case 1
A 6‑month‑old baby boy was brought to the
Dermatology OPD by his mother for brown
colored scaly lesions over his back. The
Address for correspondence:
Dr. Paschal D'souza,
Department of Dermatology,
ESI PGIMSR and Model
Hospital, New Delhi ‑ 110 015,
India.
E‑mail: paschaldsouza@yahoo.
com
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DOI: 10.4103/idoj.IDOJ_5_19
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Abstract
Sweat dermatitis is a peculiar kind of irritant inammatory dermatoses occurring due to prolonged
exposure of retained sweat over the skin. It is commonly seen in hot and dry climates like tropics
during summer months due to thermal stress. Typically, parchment paper or cellophane paper like
scaling is seen over occluded areas of back, shoulder, and other areas. Here we have reported a
varied presentation of sweat dermatitis in the form of its coexistence with miliaria rubra (impending
to thermal burn). Further we have also observed co existing pityriasis versicolor and sweat dermatitis
where the former has prevented the development of latter. Till date there is very little discussion on
this condition, so we have tried to provide a concise review about sweat dermatitis along with its
classical to atypical presentation with special emphasis on dermoscopy.
Keywords: Dermoscopy of sweat dermatitis, heat rash, sweat dermatitis
Atypical Presentation of Sweat Dermatitis with Review of Literature
Case Report
Rohini Soni,
Archana J.
Lokhande,
Paschal D'souza
Department of Dermatology,
ESI PGIMSR and Model
Hospital, New Delhi, India
How to cite this article: Soni R, Lokhande AJ,
D'souza P. Atypical presentation of sweat dermatitis
with review of literature. Indian Dermatol Online J
2019;10:698-703.
Received: January, 2019. Accepted: March, 2019.
This is an open access journal, and arcles are
distributed under the terms of the Creave Commons
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allows others to remix, tweak, and build upon the work
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For reprints contact: reprints@medknow.com
rash began as patchy erythema 4 days back
which evolved to present state. Mother gave
history of wrapping the child completely
with multiple layers of clothing to prevent
infections. There was no history of atopy.
On cutaneous examination there was
brownish “parchment”‑like, shiny skin
over the entire upper back and shoulder
region. Patchy exfoliation was also
present [Figure 1].
A diagnosis of resolving sweat dermatitis
was made and patient was given emollients.
Attendant was advised to keep infant in
cool environment and use light and loose
cotton clothing. This resulted in rapid
improvement.
Case 2
A 40‑year‑old male laborer presented to
dermatology OPD with severe itching and
burning sensation along with exfoliation
of skin over back for 1 day. He reported
history of developing these lesions
overnight after sleeping bare bodied over
the hot cement ooring of his home. There
was no history of any similar rash in the
past.
On examination there were well‑demarcated
maculopapular rashes over entire back,
which was beef red in color and studded
with multiple pinpoint vesicular eruptions
mainly towards the outer/lateral aspect.
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Soni, et al.: Sweat dermatitis
699Indian Dermatology Online Journal | Volume 10 | Issue 6 | November-December 2019
dermis. [Figure 4a and b]. Histopathology from miliaria
rubra lesion depicted sub‑corneal bullae, acantholytic cells
along with eosinophilic inltrate in the dermis [Figure 5].
Final diagnosis of sweat dermatitis was made, and patient
was started on predinsolone 30 mg daily which was
rapidly tapered and discontinued over a period of 10 days.
Topically he was asked to apply cold compresses followed
by fusidic acid and betamethasone cream twice daily.
Patient responded satisfactorily and skin condition returned
to normal in 2 weeks following exfoliation and transient
pigmentary alteration.
Case 3
A 23‑year‑old male working in a corporate ofce
presented with itching and scaling over the back since
6 days. On probing patient gave the history of traveling
for 10 hours in a non‑air‑conditioned bus 7 days back.
Cutaneous examination revealed two different types of
lesions over the back and shoulders. There were areas
of hyper pigmented coarse cigarette paper like scaling
present extensively over entire back along with few well
demarcated clear areas or apparent islands of normal skin
in between [Figure 6 Red arrow]. On dermoscopy (non
polarized view) from the pigmented area, there were
increased cutaneous markings along with deep brown
Figure 2: Erythematous maculopapular rash with studded vesicular
eruption (miliariarubra) and patchy areas of necrosis. (Case 2)
Interspersed between these dew drops like lesions, there
were patchy, irregular areas of supercial necrosis.
Exfoliation was also present in few areas [Figure 2].
A small elliptical strip of normal skin was preserved in the
lower mid back where there was pronounced grooving in
lumbar spinal region. Clinical diagnosis of acute irritant
reaction to sweat with miliaria rubra was made. Routine
hematological and biochemical investigations were
normal. On Dermoscopy (Handheld contact dermoscope:
DermLite DL3 gen. Polarized view with magnication
20×) there was diffuse background erythema interspersed
with yellowish white lacunar areas (dew drop like lesions)
probably corresponding to the obstructed sweat gland duct
opening. Scattered dark brown colored irregular stellate
areas in regions with clinical necrosis were also observed
giving a pseudo reticulate appearance along with patchy
scaling. This dermocopic nding could be described as
“Starry sky” appearance [Figure 3]. Typical white bulls eye
sign of miliaria rubra with white globules consisted of a
central white area surrounded by a darker halo forming a
dot within a dot could also be appreciated [Figure 3a‑c].
Biopsy from an area of necrosis showed focal
intraepidermal bulla formation, intraepidermal edema
and neutrophilic inltration (epidermal). There was also
presence of mononuclear and eosinophilic inltrate in the
Figure 1: Parchment-like, shiny “crinkled cellophane paper”-like skin over
the upper back in a 6 months old child (Case 1)
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Soni, et al.: Sweat dermatitis
700 Indian Dermatology Online Journal | Volume 10 | Issue 6 | November-December 2019
pigmentary changes with superimposed brownish scales
seen at few places [Figure 7].
Secondly, there were well demarcated oval to round
hyperpigmented macules on upper back, arms, neck, and
extremities having ne powdery perifollicular scales more
apparent on tangential viewing. (Figure 6: Blue arrow).
Routine blood investigations were normal. KOH
examination was performed on lesions of both morphology,
but was positive only from the hyperpigmented macules,
showing clusters of yeast cells and long hyphae consistent
with pityriasis versicolor (P. versicolor).
A nal diagnosis of resolving sweat dermatitis with
pityriasis versicolor was made. Patient was started on
emollients for sweat dermatitis, tablet uconazole 400 mg
stat and sertaconazole cream once daily application for
P. Versicolor lesions. Patient responded well with sweat
dermatitis lesions resolving with pigmentary dyschromias.
Discussion
Normal core body temperatures varies between 36°C and
37.5°C (96.8°F and 99.5°F). Sweat glands play an important
role in thermoregulation in homeothermic organisms. In
hotter months of summer especially in tropics the profuse
sweating and subsequent evaporation helps bring down the
body temperature and keeps the core body temperature in
the safe normal range.
Thermal trauma to skin can lead to myriad
presentations‑burns can occur when skin is exposed to
an external heat source with a temperature exceeding
44°C (111°F) for a sufcient period while erythema ab igne
ensues when skin is exposed to prolonged and repeated
infrared heat insufcient to cause burn.[2] Thermal stress
can also at times produce varied pattern of inammatory
dermatosis where sweat has a direct or indirect role in
causation. Review of different studies on sweat dermatitis
and possible theories causing it has been tabulated below
Figure 6: Showing two varieties of lesions. (a) Red arrow-Hyper pigmented
coarse cigarette paper like scaling over lower back of sweat dermatitis.
(b) Blue arrow-Pityriasis versicolor lesions over shoulder and upper
back. (Case 3)
Figure 5: (a) Stain from erythematous papule showing intraepidermal bullae
in sub corneal region. (b) (40 × view) H and E Stain from erythematous
papule showing intraepidermal bullae in sub corneal region with presence
of eosinophilic inltrate in the dermis. (Case 2) (10 × view) H and E
b
a
Figure 3: Dermoscopy (Handheld contact dermoscope: DermLiteDL3 gen.
(a) Polarized view with magnication 20×) shows yellowish white lacunar
areas with scattered specs of necrosis giving a ‘starry sky appearance’.
(b and c) showing white bull’s eye appearance as there is small white dot
in bigger dot (lacuna)
c
b
a
Figure 4: (a) (10 × view) H and E stain from the area of necrosis showing
focal bulla formation. (b) (40 × view) H and E stain from the area of necrosis
showing intraepidermal edema with neutrophilic inltration. There is also
presence of mononuclear and eosinophilic inltrate in the dermis. (Case 2)
b
a
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Soni, et al.: Sweat dermatitis
701Indian Dermatology Online Journal | Volume 10 | Issue 6 | November-December 2019
in Table 1. The term “Frictional sweat dermatitis” was
rst described by Ramam et al. in 1998 where they
reported 15 cases with typical friction and sweat induced
dermatitis in summer months.[3] Patients presented with
burning and stinging sensation together with roughness
and scaling where skin was in contact with under surface
of undergarments which thus produced a rash with sharp
demarcation from normal skin.[3] In 2000 Mehta et al.[1]
reported similar nding in 380 patients from Thar desert
who presented with dark brown charred plaques and
roughness of skin over inter scapular, inframammary,
axillary folds, waist band, upper chest, and back areas after
the episodes of profuse sweating.
In another study[4] involving 327 patients from same
geographical region, the authors reported this scaly
dermatosis over areas of skin covered with clothing.
Interestingly in all study participants, they found an irritant
reaction to patient’s own sweat when patch test was
performed.
Over the years this type of dermatosis has been reported
frequently not only from hot, dry states like New Delhi
and Rajasthan but also from hot, humid coastal areas
of Puducherry. Gopinath H et al.[5] has described
morphological spectrum of different sweat‑induced
dermatosis among which frictional sweat dermatitis
constituted 5.3% of patients. Histopathological picture
was seen as that of mild spongiform dermatosis. Mehta
et al. has described dermal mononuclear inltrates with
no sweat gland obstruction at any level in their cases thus
differentiating it from miliaria.[1]
Till date various triggering factors have been thought to
play a role in causation of sweat dermatitis; most of them
emphasize the role of profuse sweating, friction, prolonged
exposure of sweat‑soaked clothing or undergarment with
skin, type of clothing material (tight, porous, synthetic
non sweat absorbent), release of unrinsed detergent from
clothing,[4] pooling and retention of sweat. Recently
Chatterjee and Vasudevan[6] have proposed role of
sweat solutes and clothing material in causation of this
peculiar dermatitis. They hypothesized; individuals who
consumed less amount of uid and wore traditional
porous undergarments were more prone to develop this
Table 1: Review of dierent studies on sweat dermatitis and possible theories related to it
Study Clinical setting Clinical features and investigations Possible theories of sweat dermatitis
Ramam
et al.[3]
(New Delhi)
(1998)
1993‑1995. Months
of May and June.
Temp‑ 35°C to
45°C. 15 (11 male 4
women)
Mild stinging sensation. Elevated
plaque with a glazed, wrinkled
surface and sharp margins
corresponding to the edges of the
undergarment. BX=mild spongiotic
dermatitis.
Distribution of lesions below undergarments and other apparel
in direct contact with the skin or lower back, against which
clothing is pressed when seated, points towards frictional
contact dermatitis.
Or pressure of tight undergarments also contributes to
sweat‑soaked undergarment may keep the skin wet for several
hours before it drys out or is changed.
Sweat acts by leaching out unrinsed detergent from undergarments
Mehta et al.[1]
(Thar desert)
2000
1993‑1995. Months
of May and June,
Temp‑43°C to 47°C.
380 (M: F‑3:1)
Presented with dark brown charred
plaques. Mild burning or stinging.
BX=mild dermal mononuclear
inltrate no sweat gland obstruction
Irritant reaction to stagnant sweat at high temp and low
humidity
Chatterjee
and
Vasudevan.[6]
(Thar desert)
2015
2005‑2008. Months
of May and June.
Temp‑ 43° to 47°C.
327 (M: F‑4:1)
Patch test to patients’ own sweat
showed an irritant reaction in all
patients.
Chronic cumulative irritant contact dermatitis to sweat solutes
in individuals who consumed less uid.
Irritant reaction to seat solutes occurred in those who wore
the traditional porous undergarments which allows the uid
component of the sweat to evaporate easily, leaving the sweat
solutes which are in a higher concentration.
Gopinath
H et al.[5]
(Puducherry
2018)
April‑June
Temp‑ 23°C to
44°C. 150 pt 8 with
sweat dermatitis
Burning, stinging or “tightness” of
skin. Dry, hyperpigmented, ssured
“parchment” like skin or shiny
“crinkled cellophane paper” like
skin. BX=mild spongiotic dermatitis
Irritant reaction due to profuse sweating.
Role of occlusive clothing and friction negligible.
Figure 7: Dermoscopy showing scaling. (Handheld contact dermoscope:
DermLite DL3 gen. Polarized view with magnication 20×) (Case 3)
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Soni, et al.: Sweat dermatitis
702 Indian Dermatology Online Journal | Volume 10 | Issue 6 | November-December 2019
kind of chronic cumulative irritant contact dermatitis to
sweat solutes. Garment made up of permeable material,
allowed easy evaporation of water component of sweat,
leaving behind higher concentration of sweat solutes,
which cause this irritant reaction. In addition, water in
the sweat causes water logging which can further leads to
disruption of skin barrier function, facilitating delivery of
any potential irritant antigens.[7] Sweat also contains other
inammatory mediators including proteolytic enzymes,
urea, lactate, histamine, and cytokines such as IL‑1 a and
IL‑8. In addition, the antimicrobial peptides dermicidin and
cathelicidin could also act as irritants.[8] All these agents
could possibly contribute to development of sweat‑induced
dermatitis.[8]
In our cases described above, the rst case has a
presentation similar to previously described cases of sweat
dermatitis, including in babies. The excessive covering of
infants who have immature sweat ducts commonly cause
occlusion of ducts resulting in miliaria. In others, the
parchment like skin as in our case, due to irritant dermatitis
caused both by water and solute content of sweat may be
a manifestation. In the second and third case, however, the
manifestations were atypical.
There was a concomitant development of miliaria rubra
and sweat dermatitis after an overnight exposure of the
bare back to hot cement ooring in Case 2. Gopinath
et al.[5] described one patient out of their 150 cases who
had clinical lesions of sweat dermatitis as linear and
parallel ridges and miliaria rubra while other reports on
sweat dermatitis do not mention this association. Miliaria
is said to develop in un acclimatized or predisposed
individuals after several days of exposure to hot and
humid environment due to seepage of sweat within layers
of epidermis on account of blockage of sweat ducts while
sweat dermatitis with supercial cauterization of skin
appears within hours of the stagnant sweat irritating the
upper layers of the epidermis. It appears that in our case,
the initial profuse sweating induced by the hot cement
ooring not only directly irritated the skin occluded by
the ooring but also could have leached alkaline materials
present in the constituents of the cement ooring causing
further skin damage bordering on supercial chemical
burn. This would have also caused damage to the sweat
ducts and other appendages resulting in their occlusion
and giving a rough and dry feel to the overlying skin.
In addition, the heat retained in the ooring would have
continued to induce sweating by the sweat glands which
would have leaked intra‑epidermally to cause early miliaria
formation. The erythema could have been contributed by
inammatory response to both sweat within the skin and
sweat mixed with chemicals from without.
Dermoscopy of sweat dermatitis lesions has not been
described earlier in literature. In our Case 2, we found
miliaria as yellow lacunae “white bulls eye appearance,”
interspersed in between cauterized skin, so we coined the
term “starry sky appearance”.
In case 3, the entire back which was in direct contact with
clothing and the occlusive seating material which is usually
impervious to sweat, developed extensive sweat dermatitis,
but surprisingly spared areas involved by P. versicolor.
This is to the best of our knowledge not reported before.
P. versicolor is a supercial fungal infection which is found
as a commensal in several healthy adults but converts into
mycelial forms in certain situations including in hot and
humid conditions and manifests as scaly perifollicular
hyper or hypopigmented lesions mainly over upper chest
and back. It can also manifest as pityrosporum folliculitis.
Cutaneous lesions morphologically resembling sweat
dermatitis caused by Malassezia furfur has not been
described in the literature to the best of our knowledge.
This excludes the possibility of our case 3 having two
different cutaneous manifestations due to a fungal agent.
However, it is difcult to offer any convincing explanation
as to how this disease offered protection against sweat
dermatitis in Case 3.
Park et al. have described certain characteristics of skin
infected with P. versicolor. The lesional skin was found
to have higher hydration content and sebum secretion
along with increased Trans‑epidermal water loss (TEWL)
compared to skin of healthy non‑infected adults. The
authors believe that the hydrated and sebum rich skin
becomes a perfect medium for growth of the organisms
which then disrupt the stratum corneum to increase water
loss.[9] Whether this increase in TEWL somehow serves as
a negative feedback for the regional sweat glands to secrete
less sweat thus preventing development of sweat dermatitis
in these areas remains to be proven.
On the other hand, Lee et al. in their study found the P.
versicolor affected skin to be less hydrated than normal
surrounding skin along with having increased TEWL.[10]
This again indirectly points out to decreased activity of
sweat gland function in the regional P. versicolor affected
skin which probably explains the atypical presentation in
our case.
As elsewhere, the major pattern of sweat dermatitis
observed in our outpatient department was like case 1
i.e., parchment paper or cellophane paper like appearance.
On dermoscopy (non‑polarized view) of these lesions, there
were increased cutaneous markings along with patchy,
at places linear brownish black pigmentary changes and
superimposed scattered whitish scales (case 2).
Conclusions
A wide spectrum of sweat‑induced dermatoses is usually
seen during the summer months in a tropical country like
India, of which the predominant ones are the various types
of miliaria. However, a relatively uncommon but probably
under reported entity designated “sweat dermatitis” is
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Soni, et al.: Sweat dermatitis
703Indian Dermatology Online Journal | Volume 10 | Issue 6 | November-December 2019
being increasingly encountered and added to literature.
The unique presentation points to inammatory response
to sweat as a major causal factor in an appropriate
background of external occlusion and friction. Fortunately,
it responds well and rapidly to measures aimed at reducing
sweat secretion besides treating the acute irritant dermatitis.
The atypical presentations reect the complex response of
skin to regional variations in sweat gland density, sweat
secretion, propensity to sweat duct occlusion, presence of
commensal bacteria and yeast and their transformation to
pathogenic state. Further observations of similar cases may
help in better understanding of this entity and hopefully
enable better management.
Contribution details: special thanks to all the staff and
residents of department of Dermatology, ESI PGIMSR and
Model Hospital, New Delhi.
Declaration of patient consent
The authors certify that they have obtained all appropriate
patient consent forms. In the form the patient(s) has/have
given his/her/their consent for his/her/their images and
other clinical information to be reported in the journal. The
patients understand that their names and initials will not
be published and due efforts will be made to conceal their
identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conicts of interest
There are no conicts of interest.
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