treated with methylene blue-
daylight photodynamic therapy
Sporotrichosis is an infection caused by the dimorphic fun-
gus, Sporothrix schenckii. Acquisition typically occurs via cuta-
neous inoculation with the development of a localized
cutaneous and/or lymphocutaneous infection. Antimicrobial
photodynamic therapy (aPDT) is a process that generates reac-
tive oxygen species (ROS) in the presence of a photosensitizer,
visible light and oxygen which destroys fungal and bacterial
Daylight-PDT (DL-PDT) uses the visible spectrum of day-
light (400–750 nm) for the activation of the photosensitizer
instead of an artiﬁcial light source. It is currently approved to
treat actinic keratosis.
The band of absorption of MB is between
550 and 700 nm, with an absorption peak of 654 nm. So the
absorption peak of the methylene blue is included in the spec-
trum of the wavelength of daylight, being an option as a light
A 41-year-old man presented in the outpatient department
with a 1-year history of a plaque on his right arm. Physical
examination revealed a 2-cm, well-deﬁned erythematous nodule,
with suppuration and crust on its surface (
Fig. 1a). No lym-
phadenopathy was found.
Purulent material was submitted for bacterial, fungal and
mycobacterial microbiological studies. In sheep blood agar incu-
bation, it was observed the growth of some creamy and shiny
colonies of yeast-like aspect which showed ‘cigar bodies’ mor-
phology using Gram’s stain (Fig. 2a). And in Sabouraud agar, it
was observed the growth of white with brown centre with a ‘salt-
and-pepper’ aspect colonies, highly suggestive of Sporothrix
schenckii. (Fig. 2b).
Guidelines recommend itraconazole orally for cutaneous
sporotrichosis, for a long period of time. The patient preferred
local treatment that did not involve oral treatment to avoid sys-
temic side-effects, warning him that if treatment failure
occurred, it would require systemic treatment. Therefore,
considering the good general condition of the patient and the
presence of a single lesion, treatment with methylene blue-day-
light-PDT was proposed. PDT using 1% MB solution of intrale-
sional injection, occluded for 30 min and 2 h of daylight
exposure, was performed. After 6 sessions, 1 every 2 weeks, the
lesion showed a complete clinical and microbiological response
(Fig. 1b). The patient did not have any pain or adverse effect,
and good cosmetic and therapeutic outcome was observed. The
patient has been followed up for 1 year without any recurrence.
Cutaneous sporotrichosis is a localized form that usually
requires systemic treatment. Oral itraconazole is the preferred
treatment for cutaneous and lymphocuanteous forms of
aPDT has been previously shown effective to in vitro and
in vivo photoinactivate different types of fungi.
MB is a cationic
phenothiazinium salt, non-toxic in humans. MB-PDT has been
proven effective in vivo against chromoblastomycosis
Causative organisms of onychomycosis,
such as Trichophyton rubrum and mentagrophytes, Epidermophy-
ton ﬂoccosusm, Aspergillus niger, Candida sp. and Fusarium spp.,
have been treated with MB-PDT, concluding that it is a safe,
effective and well-tolerated treatment.
In addition, it has also
been reported in in vitro studies, which demonstrate the efﬁcacy
of MB-PDT against Trichophyton mentagrophytes.
cutaneous leishmaniasis treated with daylight-PDT experienced
no pain during the treatment.
Our group has previously shown
in vitro that MB photoinactivate more efﬁciently S. schenkii,
To our knowledge, there is only one study using
daylight-PDT with MB to treat plane warts.
This study used
10% liposomal MB gel in 40 patients with plane warts. Seventy-
ﬁve per cent of the patients showed a complete response without
any signiﬁcant systemic or phototoxic side-effects.
In conclusion, MB-PDT using daylight as the source of light
seems to be an effective and safe treatment for cutaneous
sporotrichosis. Larger studies will conﬁrm the utility of this
treatment which would be very convenient to avoid the possible
side-effects associated with standardized systemic antifungals.
Figure 1 (a) Cutaneous sporotrichosis nodule on the right arm. (b)
Complete resolution after six sessions of MB-PDT.
Figure 2 (a) Gram’s stain: ‘cigar bodies’. (b) Sabouraud agar:
© 2017 European Academy of Dermatology and Venereology
2018, 32, e86–e121
Letters to the Editor