Dapsone

Dermatitis herpetiformis REF: Journal of Investigative Dermatology Symposium Proceedings (2004) 9, 47-51 (http:// http://www.nature.com/jidsp/journal/v9/n1/full/5640132a.html) Therapy of Skin Diseases, By Yoshiki Miyachi, page 433

The responsiveness of DH to dapsone:

Responsiveness to dapsone was once considered a diagnostic criterion for DH. A number of other dermatoses clearly respond to dapsone, however and the list of dapsone-responsive dermatoses includes all of those listed in table given below. One would think that dapsone’s mechanism of action would be specifically related to IgA antibody and possibly related to neutrophil chemotaxis, but the exact mechanism by which dapsone is effective in these dermatoses has not been established. It is known that dapsone has no effect on antibody or complement deposition.

A combination therapy with steroids and Dapsone gives a better result than 1 drug used alone.

Multi drug therapy for leprosy is not contraindicated in HIV infection. WHO recommends the following drugs for treatment of multibacillary leprosy

Ans. is ‘a’ i.e., Dapsone

Ans. is ‘a’ i.e., Dermatitis herpetiformis

Dapsone is first line anti-leprotic drug.

Dapsone is also used in dermatitis herpatiformis (drug of choice), P. jiroveci infection in AIDS, actinomycetoma, rhinosporidiosis, toxoplasmosis and leishmaniasis.

MOA :

• Dapsone is an analog of para-aminobenzoic acid (PABA) and hence competitively inhibits dihydropteroate synthase (DHPS) required for folic acid synthesis.

Ans. is ‘a’ i.e., Hemolytic anaemia

The most common adverse effect of dapsone is hemolytic anaemia (Patients with G-6-PP deficiency are more susceptible).

A. i.e. 1-2 mg/kg

A i.e. 100 mg Dapsone daily + Rifampcin 600 mg monthly

Ans. is ‘a’ i.e., Rifampicin & dapsone 

Ans. A i.e. Alopecia areata

Alopecia areata (AA)

• Non-cicatricial/ non scaring alopecia
• Exclamation mark sign is characteristic
• Clinical presentation: Single or multiple circumscribed smooth patchy hair loss, most obviously on scalp but frequently involving any hair bearing skin like beard, eyebrows, eyelashes, with pathognomic “exclamation marks” and “going gray overnight” phenomenon
• AA is treated by: Minoxidil

Ans. C: Dapsone

Dermatitis herpetiformis:

• Epidemiology: Rare, male to female ratio is 2:1, onset at 20 to 40 years of age, but also in children, whites, rare in blacks or Asians
• Features: Grouped (herpetiform) excoriations or vesicles symmetrically located on extensor remission; watch for signs surfaces of elbows, knees, sacrum, buttocks, and shoulders with intense pruritus and burning sensation
• Diagnosis:

– Light microscopy: neutrophilic abscesses in dermal papillae, dermal infiltrates of neutrophils and eosinophils with subepidermal vesicles.

– Direct Immunoflorescence: granular IgA deposits in the tips of the dermal papillae

• Management: Gluten-free diet; sulfones.

Patients will experience prompt relief of lesions within one to two days of initializing treatment with dapsone or sulfapyridine.

It is important to remember to always check glucose-6-phosphate dehydrogenase (G6PD) and baseline complete blood count levels before starting dapsone, followed by complete blood cell counts every month to monitor for signs of hemolytic anemia.

Watch for signs of other autoimmune disorders; may coexist with gluten-sensitive enteropathv

Ans. is ‘b i.e., Myopathy

Adverse effects of dapsone

• The most common adverse effect of dapsone is hemolytic anaemia (Patients with G-6-PP deficiency are more susceptible).
• Second most common adverse effect is methemoglobinemia.
• Other side effects are – Nausea, anorexia, headache, paresthesia, drug fever, mental symptoms, rashes, fixed drug eruption, hypermelanosis (Pigmentation), phototoxicity, exfoliative dermatitis, hepatitis, agranulocytosis, lepra reaction and sulfone syndrome, infectious mononucleosis like syndrome.

• Tetracyclines (tetracycline, minocycline)
• Sulfonamides, other sulfa drugs
• Metronidazole, nystatin, salicylates, NSAIDs, phenylbutazone, phenacetin
• Barbiturates
• Oral contraceptives
• Quinine (including quinine in tonic water), quinidine
• Phenolphthalein
• Food coloring (yellow): in food or medications

Ans. is ‘a’ i.e., Dapsone