A case of bullous scabies 
Case report 
A CASE OF BULLOUS SCABIES 
C. Veller-Fornasa, M. Tarantello, G. Biasinutto and A. Peserico 
SUMMARY 
There are several descriptions in the literature of atypical clinical manifestations of scabies and there have 
been rare reports of pemphigoid-like bullous scabies. This case report describes a 78-year-old male who had 
been treated 6 months earlier for scabies and who came under our observation due to the onset of 
erythematous-bullous lesions on his legs and soles. The patient complained of severe pruritus and presented 
lesions due to scratching on his trunk and back, and isolated burrows on his palms and soles. Routine 
biochemical and immunologic tests revealed only an increase in total serum IgE. Histological examination 
performed on a bullous lesion showed detachment of the epidermis at the dermo-epidermal interface and a 
perivascular infiltrate rich in eosinophils. Direct and indirect immunofluorescence tests were negative. Scraping 
tests for mites performed on plantar and on the palmar lesions were positive for scabies. A diagnosis of 
bullous scabies was consequently made and topical treatment with classic acaricides was implemented, leading 
to complete remission within 15 days. 
This case seems worth to be noted because of the rarity of the clinical features and because of the strong 
resistance of skin lesions to conventional topical therapy. 
KEY WORDS 
scabies, bullous, pemphigoid-like 
INTRODUCTION 
There are several reports in the literature of 
atypical clinical manifestations of Sarcoptes scabiei 
infestation suggestive of contact dermatitis, Darier's 
disease, dermatitis herpetiformis, urticaria (1), impetigo, 
tinea, folliculitis, psoriasis, pityriasis rosea, syphilis, 
xanthoma, histiocytosis, lymphomas, or insect bites 
(2). To our knowledge, reports on scabies with 
58 
bullous pemphigoid-like manifestations are rare (1-
7). This report describes a case of bullous scabies 
that recently came under our observation. 
CASE REPORT 
A 78-year old male in fair general health came 
under our observation due to the onset of 
erythematous bullous lesions containing blood and 
acta dennatovenerologica A.P.A. Vol 5, 96, No 2 
: 
A case of bullous scabies 
Fig. l. Clinical aspect: erythematous bullous lesions on the leg. 
Fig. 2. Histopathology: detachment oj the epidennis at the denno-epidennal 
inte,face and a perivascular infiltrate rich in eosinophils. 
acta dennatovenerologica A .P.A. Vol 5, 96, No 2 
serum on his legs and soles 
(Fig. 1 ). The patient also 
presented signs of scratching 
on his trunk and back and 
isolated burrows on his palms 
and soles. He reported having 
been treated with various types 
of topical medication for 
scabies about 6 months pre-
viously, without achieving a 
complete regression of the 
pruritus. 
The biochemical and immu-
nological tests demonstrated 
an increase in total serum 
IgE to 562 kU/L (normal 
range < 200 kU/L). Lympho-
cyte subpopulation typing 
revealed an increase in CD3 
T lymphocytes to 88.6% 
(normal range 61-85%) and 
in CD8 (T suppressor-
cytotoxic) lymphocytes to 46% 
(normal range 14-42% ), and 
a drop in B activated (HLA-
DR) lymphocytes to 7.6% 
(normal range 8-28%) and 
in B lymphocytes (CD 20) to 
0.6% (normal range 3-18%). 
Histological examination of 
a biopsy from a bullous lesion 
on the leg showed detachment 
of the epidermis at the dermo-
epidermal interface. Numerous 
neutrophilic and eosinophilic 
leukocytes were found in the 
bullous lesion and in the 
underlying dermis. There was 
a considerable perivascular 
infiltrate, particularly rich in 
eosinophils (Fig. 2). Direct 
and indirect immunofluore-
scence tests (DIF and IIF) 
were negative. 
The presence of mites was 
verified by taking scrapings 
from the bullous lesions on 
the soles and palms. The 
diagnosis of bullous scabies 
was thus confirmed an,d 
treatment was implemented 
with conventional topical 
acaricide medication (benzyl 
59 
A case of bullous scabies 
benzoate 25% for 8 days and sulfur for 6 days), 
which led to the remission of the bullous lesions 
within 15 days. 
DISCUSSION 
To our knowledge, there are very few reports of 
bullous eruptions in scabies (1-6) and the clinical 
and histological signs in all reported cases were 
comparable with the findings in this case. 
In the 2 cases described by Bhawan et al. (2), 
DIF proved positive, with deposition of granular 
lgG in the basal membrane in the former and of 
linear lgG and C3 in the latter; IIF was negative, 
however. 
Viraben and Dupre (3) described the case of a 
34-year old patient with a history of recurrent 
sinusitis and pneumonia (that the authors considered 
a sign of immune deficiency) and of atopical dermatitis 
until puberty. Like our case, this patient presented 
eosinophilia and raised total serum lgE. DIF and 
IIF were negative. 
In 1993 Said et al. ( 4) described a case of 
localized bullous scabies with negative DIF and IIF 
findings. Ostlere (1), on the other hand, presented 
a case with both positive DIF findings (a linear 
band of C3 along the dermo-epidermal interface 
and perivascular deposition of IgM and C3) and 
positive IIF results (anti basal membrane 1:10). 
In percentage varying according to different authors, 
the reports in the literature mention both an increase 
in serum levels of lgE and deposits of IgG and 
complement at the dermo-epidermal interface in 
Sarcoptes scabiei infestation (8,9). 
As for the pathogenic mechanism of the bullous 
lesion, it has been suggested that an immediate 
and/or delayed hypersensitivity may be involved, in 
addition to the secretion of lytic enzymes by the 
mytes (1,3). 
Viraben and Dupre (3) suggest that primary or 
secondary immune system disorders may correlate 
in some way with the onset of atypical lesions in 
scabies and that such disorders must be suspected 
when such manifestations occur. 
It is worth mentioning that, apart from a slight 
change in the lymphocyte subpopulations, our patient 
presented no sign of immune deficiency and had 
not been administered immunosuppressants. 
Finally, as already stated by other authors, it is 
worth emphasizing that the bullous form of scabies 
presented by our patient proved rather resistant to 
conventional therapy and took a full 15 days to 
achieve complete remission. 
REFERENCE 
l. Ostlere LS, Harris D, Rustin MHA. Scabies 
associated with a bullous pemphigoid-like eruption. 
Br J Dermatol 1993; 128: 217-219. 
2. Bhawan J, Milstone E, Malhotra R, Rosenfeld T, 
Appel M. Scabies presenting as bullous pemphigoid-
like eruption. J Am Acad Dermatol 1991; 24: 179-
181. 
3. Viraben R, Dupre A. Scabies mimicking bullous 
pemphigoid. J Am Acad Dermatol 1989; 20: 134-
136. 
4. Said S, Jay S, Kang J, Liem WH, Jensen JL, 
J effes EWB. Localized bullous scabies. Am J 
Dermatopathol 1993; 15: 590-593. 
5. Bean SF. Bullous scabies. JAMA 1974; 230: 6: 
878. 
6. Triller R, De Ribes C, Barbier D, Beltzer-
Garelly E. When pemphigoid continues to be itchy. 
Medica! Staff Dermatologie 1995; 26: 10-13. 
7. Falk ES. Serum immunoglobulin values in patients 
with scabies. Br J Dermatol 1981; 105: 667-678. 
AUTHORS' ADDRESSES 
60 
Cleto Veller Fornasa MD, Ass. professor, Dpt of Dermatovenerology, University of Padova, 
Via C. Battisti n. 206, 35128 Padova, Italy 
Marco Tarantello MD, same address 
Christina Biasinutto MD, same address 
Andrea Peserico MD, PhD, Professor and Chairman, same address 
acta dermatovenerologica A.P A. Vol 5, 96, No 2