DISORDER OF SKIN APPENDAGES

TOPICS INCLUDED Acne vulgaris Rosacea Miliaria Excessive hair loss Excessive hair growth

DISORDER OF SENACEOUS GLANDS Acne vulgaris

Sebaceous glands Develop embryologically from hair germs, but a few free glands arise from the epidermis. The glands themselves are multilobed Contain cells full of lipid(sebum), which are secreted (holocrine secretion-when whole cell is secreted into the lumen)

Sebum is discharged into the upper part of the hair follicle. It lubricates and waterproofs the skin, and protects it from drying; It is also mildly bactericidal and fungistatic.

ACTIVITY Androgenic hormones, especially dihydrotestosterone, stimulate sebaceous gland activity. Human sebaceous glands contain 5α-reductase, 3α- and 17α- hydroxysteroid dehydrogenase Convert weaker androgens to dihydrotestosterone, which in turn binds to specific receptors in sebaceous glands, increasing sebum secretion. So , not the levels of circulating androgens but an enhanced target organ sensitivity which is important.

Acne Acne is a disorder of the pilosebaceous apparatus predominantly affecting the peripubertal popln andcharacterized by comedones, papules, pustules, cysts and scars.

Factors causing acne.

Prevalence Nearly all teenagers have some acne (acne vulgaris). It affects the sexes equally, starting usually between the ages of 12 and 14 years, tending to be earlier in females. The peak age for severity in females is 16–17 and in males 17–19 years. Variants of acne are much less common.

Causes of Acne vulgaris Many factors combine to cause acne characterized by chronic inflammation around pilosebaceous follicles

Sebum Sebum excretion is elevated.

Hormonal changes Androgens (from the testes, ovaries,adrenals and sebaceous glands themselves) are the main stimulants of sebum excretion, In most of the cases the level of the androgens are within normal limit but there is enhanced end organ sensitivity (incred.activity of enzyme 5-alpha reductase) Other hormones (e.g. thyroid hormones and growth hormone) have minor effects too.

Poral occlusion Occluded by keratinous plug induced by: Both genetic and environmental factors (e.g. some cosmetics) Reduced levels of linoleic acid in sebaceous gland secetions of acne patient Results in vicious cycle of retentin of sebum to growth of microbs. Distention of follicle eventually ruptures releasing pro-inflammatory chemicals into dermis stimulating intense inflammation.The ductal epithelium also produces cytokines and an inflammatory cascade is triggered.

Bacterial Propionibacterium acnes Acts as a source of antigenic stimulation,triggering a type IV inflammatory response. Produce extracellular enzymes which attract inflammatoy cells.

Factors modifying Acne Genetic predisposition(mode of inheritence not clear) The condition is familial mostly with severe cystic acne Identical twins Cosmetics Menstrual cycle Psychological factors- anger, anxiety

Presentation Polymorphic eruption: papules,pustule,comedones, nodules and cysts Lesion heals with depressed or hypertrophic scarring and Post-inflammatory hyperpigmentation can follow.

Lesions are confined to the face, shoulders, upper chest and back. Open comedones (blackheads), because of the plugging by keratin and sebum of the pilosebaceous orifice on the skin surface, or Closed comedones (whiteheads), caused by plugging below the skin surface. Associations : Most have a background of greasy skin(seborrhea) with patulous follicular openings(pores)

Acne associated with virilization May be caused by an androgen-secreting tumour of the adrenals, ovaries or testes or, rarely, congenital adrenal hyperplasia Acne accompanying the polycystic ovarian syndrome is caused by modestly raised circulating androgen levels

Variants of acne Infantile acne may follow transplacental stimulation of a child’s sebaceous glands by maternal androgens. May present at birth or may last for upto 3yrs Its morphology is like that of common acne and it may be the forerunner of severe acne in adolescence.

Mechanical. Excessive scrubbing, picking, or the rubbing of chin can rupture occluded follicles. Papulopustular lesions in an odd distribution. The patient played the violin (‘fiddler’s neck’)

Drug-induced Lesions are monomorphic and esp. over back ,face may be involved Suspicion should be raised when acne, dominated by papulopustules rather than comedones appear suddenly in a nonteenager And coincides with the prescription of a drug known to cause acneiform lesions Corticosteroids Androgenic Anabolic steroids Gonadotrophins Oral contraceptives Lithium, iodides, bromides, antituberculosis and anticonvulsant therapy can all cause an acneiform rash. Steroid-induced acne in a seriously ill patient.

Acne due to cosmetics Cosmetics esp. oil based or other topical preparations may induce comedone formation or precipitate inflammation around hair follicles.

Conglobates (gathered into balls) is the name given to a severe form of acne with all of the above features as well as abscesses or cysts with intercommunicating sinuses that contain thick serosanguinous fluid or pus. On resolution, it leaves deeply pitted or hypertrophic scars, sometimes joined by keloidal bridges. Hyperpigmentation is usually transient, it can persist, particularly in those with an already dark skin.

Fulminans Acne fulminans It is a rare variant in which conglobate acne with ulcerated and crusted lesion and is accompanied by Fever, arthralgia,myalsia and a high erythrocyte sedimentation rate (ESR).

chloracne Exogenous Tars, chlorinated hydrocarbons, oils and oily cosmetics can cause or exacerbate acne. Suspicion should be raised if the distribution is odd(forearm, legs)or unusal age(mid age male) or if comedones predominate

Excoriated This is most common in young girls. Obsessional picking otherwise mild acne Results in excoriations on face while primary lesions not visible

Late onset This too occurs mainly in women Is limited to the chin. Nodular and cystic lesions are predominant. It is stubborn and persistent.

Tropical This occurs mainly on the trunk and may be conglobate.

Acne after facial massage Acne following (3-6 wks later) in abt 30% of patients Nodules with few comedones Along mandibular region

Course Acne vulgaris clears by the age of 23–25 years in 90% of patients, Some (5% of women and 1% of men) still need treatment in their thirties or even forties.

Investigations None are usually necessary. Cultures are occasionally needed to exclude a pyogenic infection, an anaerobic infection or Gram-negative folliculitis.

Any acne, including infantile acne, that is associated with virilization needs investigation to Exclude an androgen-secreting tumour of the adrenals, ovaries or testes To rule out congenital adrenal hyperplasia

Differential diagnosis Rosacea affects older individuals Pyogenic folliculitis Hidradenitis suppurativa is associated with acne conglobata, but attacks the axillae and groin. Pseudofolliculitis barbae, caused by ingrowing hairs, occurs on the necks of men with curly facial hair and clears up if shaving is stopped.

Treatment General measures Acne frequently has marked psychological effects. Even those with mild acne need sympathy, optimistic approach is essential, and regular encouragement is worthwhile. Local hygiene, diet, stress

Local treatment 1 Regular gentle cleansing with mild soap and water Benzoyl peroxide. This antibacterial agent plus decreases inflammation applied only at night initially, but can be used twice daily if this does not cause too much dryness and irritation. Retinoic Acid(RA)/tretinoin The vitamin A (retinol) analogues (tretinoin, isotretinoin, adapalene,(recently introducedand less irritent) ,tazarotene)normalize follicular keratinization, and reduce sebum production and reduce inflammation,decrease p.acne They are especially effective against comedones. Patients should be warned about skin irritation (start with small amounts) and photosensitivity.

The weakest preparation should be used first, and applied overnight on alternate nights. Sometimes, after a week or two, it will have to be stopped temporarily because of irritation. The combination of benzoyl peroxide in the morning and tretinoin at night has many advocates. Isotretinoin 0.05%, 0.025%, 0.1% Other agents Azelaic acid :reduce post acne hyperpigmentation Alpha hydroxy acids eg. Glycolic acid

Topical antibiotics Topical clindamycin, erythromycin and sulfacetamide Cosmetic camouflage- Cover-ups help some patients, especially females, whose scarring is unsightly. They also obscure post-inflammatory pigmentation.

Systemic treatment Antibiotics tetracycline includes:doxycycline and minocycline mostly used and less frequently erythromycin and azithromycin Used in mod. to severe acne and in those who are having psy. problem Tetracycline-1gm,doxycycline- 100mg,minocycline-100mg, erythromycin- 1gm, azithromycin-250mg daily for long periods of time up to 6 mths or even longer. It should be taken on an empty stomach, 1 h before meals or 4 h after food

Oral antibiotics should be combined with topical agents because then it is possible to withdraw the antibiotic and maintain in topical therapy. Side effects: GI disturbance Vaginal candidiasis Resistance Grayish pigmentation in case of minocycline To be avoided in pregnancy.

Hormonal Antiandrogenics only for females Cyproterone acetate, a combined antiandrogen– oestrogen treatment Combined oral contraceptives Spironolactone Isotretinoin- for severe intractable acne Severe acne,conglobata Relapses Side effects:dryness of skin, eye,nose bleed,initial aggravation of inflammation , myalsia, altered night vision and hair loss, avoided in pregnancy, Careful monitoring with blood pictures and pregnancy test before and after starting rx

Acne scar treatment Dermabrasion This helps to smooth out facial scars. Lasers Skin resurfacing with CO2 and erbium lasers is rapidly replacing dermabrasion and chemical peeling Dermal fillers Bovine collagen or hyaluronic acid fillers can be injected into depressed scars to improve their appearance. Cryotherapy Intralesional corticosterois

ROSACEA

definition Rosacea is a chronic skin disorder characterized by erythema and telangiectasia and punctuated by acute episodic eruption of papules, pustules and swelling.

Rosacea affects the face of adults, usually women. Although its peak incidence is in the thirties and forties, it can also be seen in the young or old. It may coexist with acne.

cause Rosacea is often seen in those who flush easily in response to warmth, spicy food, alcohol or embarrassment. Hereditary component Fair-skinned Psychological abnormalities chemicals, high dosages of isotretinoin, benzoyl peroxide and tretinoin. A pathogenic role for the follicular mite dermodex folliculorum as well as for microaerophilic gm negetive bacterium. Helicobacter pylori is suspected but has not been confirmed.

sites The cheeks, nose, centre of forehead and chin are most commonly affected The periorbital and perioral areas are usually spared Lymphoedema, below the eyes and on the forehead, is seen in few cases Intermittent flushing is followed by a fixed erythema and telangiectases. Discrete domed inflamed papules, papulopustules and, rarely, plaques or nodules develop No comedones or seborrhoea

Usually symmetrical Exacerbations and remissions

types 1. Papulopustular rosacea Inflammatory lesions are predominant Some permanent redness with red papules with some pus filled pustules (typically last 1- 4 days); this subtype can be easily confused with acne.

Types.. 2. Erythematotelangiectatic rosacea Vascular features predominate Permanent redness / erythema with a tendency to flush and blush easily. Small blood vessels are usually visible near the surface of the skin k/a telangiectases, sometimes associated with burning or itching sensations.

Types… 3. Phymatous type This subtype is most commonly associated with rhinophyma, an enlargement of the nose. Symptoms include thickening of skin, irregular surface, nodularities, and enlargement of nose. Phymatous rosacea can also affect chin (gnatophyma), forehead (metophyma), eyelids (blepharophyma), and ears (otophyma). Small blood vessels may be visible near the surface of the skin (telangiectases). .

types 4. Ocular type Red, dry and irritated eyes and eyelids. Some other symptoms include foreign body sensations, itching and burning

Complications Rhinophyma Blepharitis Conjunctivitis Keratitis lymphedema

Rhinophyma Hyperplasia of the sebaceous glands and connective tissue of the nose Common in males

Differential diagnosis Acne Seborrhoeic eczema Perioral dermatitis Systemic lupus erythematosus Photodermatitis Menopausal symptoms Superior venacaval obstruction

Differentiating rosacea from acne Absence of comedones Comedones are present Affects the central face, no trunk involvement Diffusely over face, trunk involvement is present Appears after adolescence Usually teenagers Erythema and telangiectases Telangiectases are not seen

Treatment Topical agents Topical metronidazole (0.75% metronidazole gel) Retinoic acids Corticosteroids not to be used Systemic therapy: Antibiotics- tetracyclines-start with 1 gm a day reduce dose to 250mg daily over a period of 2-3 ,months ,as the lesions respond Erythromycin second choice Metronidazole Isotretinoin 1mg/kg body weight daily for 3- 6mths

Various techniques can be used to improve the appearance of disfiguring rhinophymas Surgical excision Cryotherapy Electrocautery Argon or CO2 laser ablation.