Table 1: Differences between bullous Darier’s disease and Hailey-Hailey disease^1-4,9-12

Bullous Darier’s Disease	Familial Benign Pemphigus
I. Genetic
1. Mutation in SERCA 2 gene on chr. 12q 23-24.1	Mutation in genes^11,12 encoding golgi secretory pathway CA^+2 ATPase (SPCA1 ATP2 (1) on chr. 3q 21-q24
II Clinical Features
2. Onset in 1^st/2^nd decade	Onset in 3^rd/4^th decade
3. Males = Females	Males > Females
4. Low familial incidence	High familial incidence
5. Warty, greasy, malodourous papules Vesicles to bullae present over the seborrhoeic sites.	Primary lesion is a flaccid vesicles and blisters on flexural sites which soon rupture because of friction and secondary infection. It is more common to find eroded, macerating, vegetating plaques
6. Lesions develop slowly	Lesions develop rapidly
7. Lesions static. Lesions never disappear permanently and progress to involve the entire body	Lesions disappear entirely, leaving no macroscopic changes except temporary pigmentation.
8. Recurrence of lesions are not seen because they are irreversible unless specific treatment is initiated	Recurrence is characteristic^10
9. Condition worsens in older people progressive	Condition improves in older people. Attacks are milder and less frequent as years go by
10. Conjunctiva and cornea not attached	Conjunctiva and cornea may be attacked and has been reported
11. Palms and soles involved	Palms and soles normal
12. Nails may be involved	Nails not involved
13. Nikolsky sign negative	Nikolsky sign often positive
III Histology
14. Hyperkeratosis and follicular plugging`	Usually absent
15. Suprabasal clefts – smaller	Larger- lacunae exend laterally
16. Dyskeratotic cells (corps ronds and grains) more evident	Less evident
17. Acantholytic cells: less evident	More evident. Foci of “dilapidated brick wall appearance “
IV Response To Treatment
a) Topical and systemic steroids b) No response to antibiotic treatment c) Oral retinoids have a variable response and in vivo systemic retinoids induce desquamation and skin fragility and aggravate lesions in bullous dariers.	a) Topical antibiotics/antifungals – tetracyclines, fusidic acid, imidazoles b) Systemic steroids – short course in case of acute exacerbation c) Other-drugs–dapsone,cyclosporine,Grenz rays d) Methotrexate and retinoids in resistant cases