Drug Eruption and Interactions - PHARMACEUTICAL REVIEW

646 DESCRIPTION OF THE 34 MOST COMMON REACTION PATTERNS
Aphthous stomatitis
Aphthous stomatitis – also known as canker sores – is a common
disease of the oral mucous membranes.
Arising as tiny, discrete or grouped, papules or vesicles,
these painful lesions develop into small (2–5 mm in diameter),
round, shallow ulcerations having a grayish, yellow base
surrounded by a thin red border.
Located predominantly over the labial and buccal
mucosae, these aphthae heal without scarring in 10–14 days.
Recurrences are common.
Baboon syndrome
The Baboon Syndrome is an unusual presentation of a drug
eruption with a characteristic intertriginous distribution pattern.
Several drugs have been implicated, notably mercury,
nickel, heparin, aminophylline, pseudoephedrine,
terbinafine, IVIG, various antibiotics (amoxicillin, ampicillin),
and food additives.
Originally described as a type of systemic contact dermatitis
characterized by a pruritic exanthems involving the buttocks
and major flexures – groins and axillae, some
investigators believe that this entity is a form of recall phenomenon.
In children, it is important in the differential diagnosis
of viral exanthems.
Black hairy tongue (lingua villosa nigra)
Black hairy tongue (BHT) represents a benign hyperplasia of
the filiform papillae of the anterior two-thirds of the tongue.
These papillary elongations, usually associated with black,
brown, or yellow pigmentation attributed to the overgrowth
of pigment-producing bacteria, may be as long as
2 cm.
Occurring only in adults, BHT has been associated with
the administration of oral antibiotics, poor dental hygiene,
and excessive smoking.
Bullous eruptions
Bullous and vesicular drug eruptions are diseases in which
blisters and vesicles occur as a complication of the administration
of drugs. Blisters are a well-known manifestation of
cutaneous reactions to drugs.
In many types of drug reactions, bullae and vesicles may
be found in addition to other manifestations. Bullae are usually
noted in erythema multiforme, Stevens–Johnson syndrome,
toxic epidermal necrolysis, fixed eruptions when
very intense, urticaria, vasculitis, porphyria cutanea tarda,
and phototoxic reactions (from furosemide and nalidixic
acid). Tense, thick-walled bullae can be seen in bromoderma
and iododerma as well as in barbiturate overdosage.
Common drugs that cause bullous eruptions and bullous
pemphigoid are: nadalol, penicillamine, piroxicam,
psoralens, rifampin, clonidine, furosemide, diclofenac,
mefenamic acid, bleomycin, and others.
DRESS syndrome
The DRESS syndrome is an acronym for Drug Rash with
Eosinophilia and Systemic Symptoms. It is also known as the
Drug-Induced Pseudolymphoma and Drug Hypersensitivity
Syndrome.
Erythema multiforme and Stevens–Johnson
syndrome
Erythema multiforme is a relatively common, acute, self-limited,
inflammatory reaction pattern that is often associated
with a preceding herpes simplex or mycoplasma infection.
Other causes are associated with connective tissue disease,
physical agents, X-ray therapy, pregnancy and internal malignancies,
to mention a few. In 50% of the cases, no cause can
be found. In a recent prospective study of erythema
multiforme, only 10% were drug related.
The eruption rapidly occurs over a period of 12 to 24
hours. In about half the cases there are prodromal symptoms
of an upper respiratory infection accompanied by
fever, malaise, and varying degrees of muscular and joint
pains.
Clinically, bluish-red, well-demarcated, macular, papular,
or urticarial lesions, as well as the classical ‘iris’ or ‘target
lesions’, sometimes with central vesicles, bullae, or purpura,
are distributed preferentially over the distal extremities,
especially over the dorsa of the hands and extensor aspects
of the forearms. Lesions tend to spread peripherally and may
involve the palms and trunk as well as the mucous membranes
of the mouth and genitalia. Central healing and overlapping
lesions often lead to arciform, annular and gyrate
patterns. Lesions appear over the course of a week or 10
days and resolve over the next 2 weeks.
The Stevens–Johnson syndrome (erythema multiforme
major), a severe and occasionally fatal variety of erythema
multiforme, has an abrupt onset and is accompanied by any
or all of the following: fever, myalgia, malaise, headache,
arthralgia, ocular involvement, with occasional bullae and
erosions covering less than 10% of the body surface. Painful
stomatitis is an early and conspicuous symptom. Hemorrhagic
bullae may appear over the lips, mouth and genital
mucous membranes. Patients are often acutely ill with high
fever. The course from eruption to the healing of the lesions
may extend up to 6 weeks.
The following drugs have been most often associated with
erythema multiforme and Stevens–Johnson syndrome:
allopurinol, lamotrigine phenytoin, barbiturates,
carbamazepine, estrogens/progestins, gold, NSAIDs,
penicillamine, sulfonamides, tetracycline, and tolbutamide.