ARTICLE
A 65-year-old white man with non-insulin dependent diabetes mellitus
and coronary artery disease presented with a one-year history of mildly
pruritic nummular plaques over the arms and legs. The lesions began as
small red papules and plaques and gradually expanded concentrically despite
treatment with multiple topicals. There was no history of prior skin disease,
and he denied associated constitutional symptoms. Other past medical history
included a toe amputation for peripheral vascular disease and a cholecystectomy
for cholelithiasis. His medications included metformin, troglitazone,
repaglinide, and fenofibrate, none of which were newly prescribed. Review
of systems was negative except for worsening numbness and paresthesias
in a stocking-glove distribution, attributed to diabetic neuropathy. The
patient was a retired teacher and sports coach and enjoyed recreational
game hunting in central Texas. There was no known history of direct contact
with armadillos.
On examination, there were multiple nontender annular plaques distributed
asymmetrically over the arms and legs. All plaques appeared similar, with
raised erythematous borders, dusky centers, and clearing in between (Fig.
1). There was no anesthesia within the plaques and no nerve cords
were palpable. The face was normal in appearance, and the groin and axillae
were spared.
On routine histologic sections with hematoxylin and eosin staining,
there was a marked histiocytic infiltrate with giant cells within the
dermis (Fig. 2), concentrated
around nerve bundles and vessels (Fig.
3). This granulomatous infiltrate was accompanied by abundant
lymphocytes. A Fite stain of the same biopsies revealed abundant acid-fast
bacilli, some of which were present within the cytoplasm of histiocytes,
at a density of between 100-1,000 organisms per oil-immersion field (Fig.
4).
The heavy burden of organisms on the Fite stain corresponded to a bacterial
index of 5+, constituting a diagnosis of subpolar lepromatous
leprosy.
The patient was referred to a leprosy treatment clinic where routine
triple drug therapy with rifampin, dapsone, and clofazamine was started.
Within two weeks, the lesions completely resolved and the numbness and
parasthesias of the hands and feet improved significantly. Because of
gastrointestinal intolerance, the rifampin and clofazamine were discontinued.
The patient has now remained without skin lesions for four months on daily
dapsone alone.
Discussion
Leprosy, also known as Hansen's disease, is a chronic granulomatous
disease caused by an acid fast rod Mycobacterium leprae which primarily
affects skin and nerves [1]. Worldwide cases have fallen from 5.4 million
in 1995 to below 1 million in 1998 [2] and in the United States, Southern
Louisiana and Texas are considered endemic for leprosy [3]. Mode of transmission
is unknown, but postulated to occur via the nasal mucosa of untreated
leprosy patients and may also involve direct skin-to-skin contact [2,
3]. Clinically, two very helpful features are a skin eruption and areas
of cutaneous anesthesia [1] other features are nerve enlargement, nasal
stuffiness, inflammatory eye changes, and loss of lateral eyebrows [4].
Depending on the immune response of the host, leprosy can manifest in
several different ways, and has many different classification systems.
The Ridley-Jopley classification is commonly used although it was originally
intended for research purposes only [5]. This system divided leprosy into
tuberculoid and lepromatous leprosy, and included indeterminate and borderline
types (Table I). WHO uses a more simplified approach in order to
guide therapy, using only two groups based simply on bacterial indices:
paucibacillary leprosy for an index of less than 2+ on the
Ridley scale and multibacillary leprosy diagnosed with a 2+
or greater bacterial index [5]. Clinically, tuberculoid leprosy usually
presents as a single sharply demarcated, hypopigmented, hypesthetic macule
with a circinate elevated border [1]. Often the nerves at the edge of
the lesion are thickened, and peripheral nerves can be enlarged [1]. Lepromatous
leprosy is more generalized, involving the skin, upper respiratory mucous
membranes, and multiple other organs [3]. Lesions are classically described
as small, ill-defined, bilaterally symmetric, flesh-colored, erythematous
or slightly hypopigmented macules, which progress to papules, plaques,
nodules, and diffuse thickening of the skin [3].
Several findings make this patient's presentation of subpolar lepromatous
leprosy atypical. The patient's lesions were targetoid, which is not the
classical description of lepromatous lesions. Also, the fact that the
lesions were asymmetrically distributed is more typical of the tuberculoid
and borderline tuberculoid subtypes.
Diagnosis is made by demonstrating cutaneous anesthesia, by finding
enlarged cutaneous nerves, or by demonstrating lepra bacilli in the skin
[6]. It is preferable to get a skin biopsy from the affected area and
a special stain for leprosy must be requested, such as the Fite stain,
a modified acid-fast stain [3]. The lepromin skin test, similar to the
tuberculin skin test, can help confirm the leprosy type but is not used
for diagnosis [4].
Because of high resistance worldwide, WHO (World Health Organization)
recommends multidrug therapy: paucibacillary patients receive 600 mg rifampin
monthly, supervised, and 100 mg dapsone daily, unsupervised, for 6 months,
at which time therapy is discontinued [2]. In 1997 the 7th WHO Expert
Committee on Leprosy recommended that single-lesion paucibacillary leprosy
could be treated with a single dose of therapy consisting of 600 mg rifampin,
400 mg ofloxacin, and 100 mg minocycline [2, 7]. Multibacillary cases
are treated with 600 mg rifampicin and 300 mg clofazimine monthly, supervised,
and 100 mg dapsone and 50 mg clofazimine daily, unsupervised, for 12 months
according to the 7th Expert committee [2, 7]. In most cases treated in
the United States, these WHO guidelines are often supplemented with either
longer treatment times or daily, instead of weekly, doses of rifampin.
It is generally accepted that treatment should be individualized as long
as WHO guidelines are fulfilled.
The current standard United States regimen for paucibacillary
leprosy is dapsone 100 mg daily plus rifampin 600 mg for 6 months, followed
by dapsone monotherapy for 3 years (indeterminate and TT) or 5 years (BT).
For multibacillary leprosy the current standard United States regimen
is dapsone 100 mg daily plus rifampin 600 mg daily for 3 years, followed
by dapsone monotherapy for 10 years (BB) or life (BL or LL).
Complications of leprosy include severe neuritic pain, contractures
and crippling of the hands and feet, neuropathic plantar ulcers, secondary
infections, saddlenose deformity and nasal obstruction, infertility, and
blindness [4].
References
1. Rea TH, Modlin RL. Leprosy. In: Freedberg IM, Eisen AZ, Wolff
K, et al. eds. Fitzpatrick's Dermatology in General Medicine.
5th edition. New York: McGraw-Hill; 1999: 2306-18.
2. Jacobson RR, Krahenbuhl JL. Leprosy. Lancet 1999; 353:
655-60.
3. Golitz LE. Leprosy (Hansen's disease). In: Fitzpatrick JE,
Aeling JL, eds. Dermatology secrets. Philadelphia, Hanley &
Belphus, Inc; 1996 : 188-94
4. Miller RA. Leprosy (Hansen's Disease). In: Fauci, et al.
Harrison's principles of internal medicine. 14th edition. New York:
McGraw-Hill, 1998: 1014-9.
5. Dharmendra. Classifications of leprosy. In: Hastings RC, Opromolla
DVA, eds. Leprosy. 2nd edition. New York: Churchill Livingstone,
1994: 179-90.
6. Pfaltzgraff RE, Ramu G. Clinical leprosy. In: Hastings RC,
Opromolla DVA, eds. Leprosy. 2nd edition. New York: Churchill Livingstone,
1994: 237-87.
7. Single-lesion Multicentre Trial Group. Efficacy of a single
dose multidrug therapy for treatment of single-lesion paucibacillary leprosy.
Indian J Lepr 1997; 69: 121-9.
Acknowledgements
We thank Drs. Terry Williams and Norman May for providing the patient.
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