Causes of Irreversible, Scarring Type of Patchy Hair Loss

Aug 18, 2011
Hanish Babu

Lichen Plano Pilaris: Causes Itchy Scalp and Scarring Alopecia. - Dr.Hanish Babu, MD

Certain skin and hair diseases cause permanent damage to the skin and the hair follicle with resultant scar formation and patchy hair loss.

The chances of hair growing again in scarred, bald scars are rare to nil. The skin usually appears smooth, thinned out or thickened depending upon the underlying disease. Most important, compared to the reversible non-scarring alopecia, hair follicles are completely obliterated in the patchy scarring hair loss.

Diseases causing scarring type of permanent patchy loss of hair may be categorized under the headings of skin infections, autoimmune skin diseases and inflammatory or allergic skin disorders.

Skin Infections Causing Permanent Scarring and Irreversible Patchy Hair Loss

Many deep seated skin and hair infections, if not treated early with appropriate cleansing measures and antibiotics, can cause permanent scarring alopecia. These include the following conditions:

Folliculitis decalvans. Recurrent, severe infection of the hair follicles, usually caused by the Staph.aureus, can result in scarring and hair loss. The infection in Folliculitis decalvans is deep and presents with interconnecting boggy swellings.
Dissecting cellulitis of scalp. Commonly seen in black men, dissecting cellulitis is caused primarily by Staph.aureus. The deep infection causes painful fluctuant swellings on the scalp. Adjacent bumps coalesce to form large pus filled sacs. Because of the deep involvement, healing results in patches of scarred bald spots.
Post inflammatory scarring in severe infections, as in sycosis barbae, acne keloidalis nuchae and shingles. Severe, destructive and necrotic type of shingles involving the scalp and beard can result in permanent scarring and patches of hair loss.
Kerion or inflammatory tinea capitis usually presents with a boggy swelling studded with pus filled hair follicles and the surface showing scaling and crusting from dried up exudates. The patch is usually round with broken hairs, and, later, absent hairs. If early treatment is not instituted, prolonged inflammatory reaction in this type of scalp ring worm infection will destroy the hair follicles with resultant permanent bald scars.
Acne necrotica. Severe, nodulocystic acne, if not treated early, can result in necrosis of the hair bearing facial skin. Healing results in scars and patches of hair loss in the affected area.

Autoimmune Skin Diseases Resulting in Irreversible, Patchy Loss of Hair

Systemic lupus erythematosus and scleroderma can cause both disseminated hair loss and patchy alopecia. Most important manifestation of localized scarring hair loss in SLE is the discoid lupus erythematosus.

Discoid lupus erythematosus. This is a manifestation of chronic cutaneous lupus erythematosus, initially presenting as red colored thick plaques of hair loss with hard plugs replacing the hairs within the hair follicles. This is called the ‘carpet tacks’ sign. Later, there is loss of pigment within the plaque and gradual thinning as the scar ages.
Scleroderma. Localized patches of scleroderma (morphea) can result in scarring hair loss on the scalp.

Scarring Alopecia Caused by Inflammatory and Allergic Skin Conditions

Lichen planus, alopecia mucinosa, pseudopelade of Brocq, central centrifugal scarring alopecia and certain chemical burns and recurrent severe skin allergic responses can result in scarred bald spots on the scalp and elsewhere on the hair bearing areas of the body.

Lichen planus. Lichen planus, an inflammatory allergic disorder of the skin, can affect the hair follicles of the scalp and other hair bearing areas, resulting in permanent scarring and hair loss. The involvement of the scalp may or may not be accompanied by violaceous, itchy bumps on other body parts. Lichen plano pilaris or follicular lichen planus is one of the causes of itchy scalp. Initial lesions can be painful too. The scar tissue has a violaceous hue most of the time and the skin may become thickened or atrophic depending upon the severity of the inflammatory response in the dermal layer of the skin.
Alopecia mucinosa. Also known as follicular mucinosis, alopecia mucinosa presents as reddish bumps or patches on the scalp and face with scarring hair loss. Alopecia Mucinosa is often a manifestation of Cutaneous T cell lymphoma.
Pseudopelade of Brocq. Pelade is another name for alopecia areata. Because of the clinical resemblance to alopecia areata, this condition was named as pseudopelade by Brocq. It is the final stage of all inflammatory and non-inflammatory scarring hair losses where the cause cannot be pinpointed for sure. Early hair loss resembles the moth eaten pattern of secondary syphilis; later these bald patches coalesce to form large patches of hair loss and are termed ‘footprints in the snow’ hair loss.
Central centrifugal scarring alopecia. A type of pseudopelade, CCSA is typically seen in black women who use chemical straighteners and hot combs on a regular basis. Chronic pulling on the hair roots due to tight hair styling is an added cause. These, alone or in combination, cause gradual degeneration of the hair follicles, resulting in irreversible scarring alopecia.

How to Find Out the Cause of the Irreversible Scarring Type of Patchy Hair Loss

Clinical appearance is usually sufficient for an experienced dermatologist to make a correct diagnosis and institute early treatment. It is to be noted that once scarring sets in, the hair loss is permanent. Hence early diagnosis and treatment, especially of the patchy alopecia of infective origin, is important in preventing irreversible damage to the skin and hair follicles.

The following laboratory tests will help in diagnosing the exact cause in most cases of scarring patchy hair loss:

Culture and sensitivity test of the pus from the boggy swellings
Potassium hydroxide preparation to confirm/rule out fungal infection
Scalp biopsy. Usually two punch biopsies of 4 mm depth are taken from the margin, one for horizontal section and the other for vertical section and direct immunofluorescence studies.

How to Treat the Scarring Type of Irreversible Patchy Hair Loss

Early diagnosis and aggressive intervention is required to prevent the irrevocable scarring in this type of patchy hair loss. In diseases like kerion, early aggressive anti-inflammatory and antifungal therapy will result in healing of the lesion without scarring or permanent hair loss. This is also true with infective diseases like dissecting cellulitis, folliculitis decalvans and herpes zoster.

Though most of the diseases discussed here cause irreversible scarred bald patches, timely treatment does help in reducing the severity of the tissue destruction. It is beneficial for the patient to differentiate between the scarring and non-scarring types of patchy hair loss. This will help in accurately assessing the normal course and final outcome of the disease process.

References

Ralf P, Elis AO, Andrew GM. Hair Growth Disorders, in Fitzpatrick’s Dermatology in General Medicine., 7th Ed, 1: 753-777, 2008
Messenger AG et al. Disorders of Hair, in Rook’s Text Book of Dermatology, 8th Ed, 4: 66.1-66.100, 2010
Klaus W, Richard AJ. Skin Signs of Hair, Nail, and Mucosal Disorders, in Fitzpatrick’s Color Atlas & Synopsis of Clinical Dermatology, Sixth Ed, 961-1067, 2009.

Disclaimer

The information given in this article is for educational purpose only so that patients are aware of the options available. No diagnosis should be made or treatment undertaken without first consulting your doctor. If you do so, the author or suite101 will not be responsible for any consequences. The images provided are for illustration purpose only.

Hanish Babu - Dr.Hanish Babu, MD is a dermatologist and a feature writer on Suite101.com with more than 200 articles related to skin diseases on the ...